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1.
Lasers Surg Med ; 55(4): 423-436, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36884000

RESUMO

OBJECTIVE: Fluorescence-based methods are highly specific and sensitive and have potential in breast cancer detection. Simultaneous fluorescence imaging and spectroscopy during intraoperative procedures of breast cancer have great advantages in detection of tumor margin as well as in classification of tumor to healthy tissues. Intra-operative real-time confirmation of breast cancer tumor margin is the aim of surgeons, and therefore, there is an urgent need for such techniques and devices which fulfill the surgeon's priorities. METHODS: In this article, we propose the development of fluorescence-based smartphone imaging and spectroscopic point-of-care multi-modal devices for detection of invasive ductal carcinoma in tumor margin during removal of tumor. These multimodal devices are portable, cost-effective, noninvasive, and user-friendly. Molecular level sensitivity of fluorescence process shows different behavior in normal, cancerous and marginal tissues. We observed significant spectral changes, such as, red-shift, full-width half maximum (FWHM), and increased intensity as we go towards tumor center from normal tissue. High contrast in fluorescence images and spectra are also recorded for cancer tissues compared to healthy tissues. Preliminary results for the initial trial of the devices are reported in this article. RESULTS: A total 44 spectra from 11 patients of invasive ductal carcinoma (11 spectra for invasive ductal carcinoma and rest are normal and negative margins) are used. Principle component analysis is used for the classification of invasive ductal carcinoma with an accuracy of 93%, specificity of 75% and sensitivity of 92.8%. We obtained an average 6.17 ± 1.66 nm red shift for IDC with respect to normal tissue. The red shift and maximum fluorescence intensity indicates p < 0.01. These results described here are supported by histopathological examination of the same sample. CONCLUSION: In the present manuscript, simultaneous fluorescence-based imaging and spectroscopy is accomplished for the classification of IDC tissues and breast cancer margin detection.


Assuntos
Neoplasias da Mama , Carcinoma Ductal , Humanos , Feminino , Neoplasias da Mama/cirurgia , Sistemas Automatizados de Assistência Junto ao Leito , Análise Espectral , Imagem Óptica
2.
Indian J Plast Surg ; 56(5): 413-420, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-38026769

RESUMO

Introduction Large language models (LLMs) are designed for recognizing, summarizing, translating, predicting, and generating text-based content from knowledge gained from extensive data sets. ChatGPT4 (Generative Pre-trained Transformer 4) (OpenAI, San Francisco, California, United States) is a transformer-based LLM model pretrained on public data as well as data obtained from third-party sources using deep learning techniques of fine tuning and reinforcement learning from human feedback to predict the next text. We wanted to explore the role of LLM as a teaching assistant (TA) in plastic surgery. Material and Methods TA roles were first identified in available literature, and based on the roles, a list of suitable tasks was created where LLM could be used to perform the task. Prompts designed to be fed in to the LLM (specifically ChatGPT) to generate appropriate output, were then created and fed to the ChatGPT model. The outputs generated were scored by evaluators and compared for interobserver agreement. Results A final set of eight TA roles were identified where a LLM could be utilized to generate content. These contents were scored for usefulness and accuracy. These were scored independently by the eight study authors in a scoring sheet created for the study. Interobserver agreements for content accuracy, usefulness, and clarity were 100% for content generated for the following: interactive case studies (generation), simulation of preoperative consultations, and generation of ethical considerations. Discussion LLMs in general and ChatGPT (on which this study is based) in specific, can generate answers to questions and prompts based on huge amount of text fed into the model for training the underlying language model. The answers generated have been found to be accurate, readable, and even indistinguishable from human-generated text. This capability of automated content synthesis can be exploited to generate summaries to text, answer short and long answers, and generate case scenarios. We could identify a few such scenarios where the LLM could in general be utilized to play the role of a TA and aid plastic surgery residents in particular. In addition, these models could also be used by students to obtain feedback and gain reflection which itself stimulates critical thinking. Conclusion Incorporating LLMs into the educational arsenal of plastic surgery residency programs can provide a dynamic, interactive, and individualized learning experience for residents and prove to be worthy TAs of future.

3.
Clin Infect Dis ; 75(1): e368-e379, 2022 08 24.
Artigo em Inglês | MEDLINE | ID: mdl-35323932

RESUMO

BACKGROUND: In locations where few people have received coronavirus disease 2019 (COVID-19) vaccines, health systems remain vulnerable to surges in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections. Tools to identify patients suitable for community-based management are urgently needed. METHODS: We prospectively recruited adults presenting to 2 hospitals in India with moderate symptoms of laboratory-confirmed COVID-19 to develop and validate a clinical prediction model to rule out progression to supplemental oxygen requirement. The primary outcome was defined as any of the following: SpO2 < 94%; respiratory rate > 30 BPM; SpO2/FiO2 < 400; or death. We specified a priori that each model would contain three clinical parameters (age, sex, and SpO2) and 1 of 7 shortlisted biochemical biomarkers measurable using commercially available rapid tests (C-reactive protein [CRP], D-dimer, interleukin 6 [IL-6], neutrophil-to-lymphocyte ratio [NLR], procalcitonin [PCT], soluble triggering receptor expressed on myeloid cell-1 [sTREM-1], or soluble urokinase plasminogen activator receptor [suPAR]), to ensure the models would be suitable for resource-limited settings. We evaluated discrimination, calibration, and clinical utility of the models in a held-out temporal external validation cohort. RESULTS: In total, 426 participants were recruited, of whom 89 (21.0%) met the primary outcome; 257 participants comprised the development cohort, and 166 comprised the validation cohort. The 3 models containing NLR, suPAR, or IL-6 demonstrated promising discrimination (c-statistics: 0.72-0.74) and calibration (calibration slopes: 1.01-1.05) in the validation cohort and provided greater utility than a model containing the clinical parameters alone. CONCLUSIONS: We present 3 clinical prediction models that could help clinicians identify patients with moderate COVID-19 suitable for community-based management. The models are readily implementable and of particular relevance for locations with limited resources.


Assuntos
COVID-19 , Adulto , COVID-19/diagnóstico , Progressão da Doença , Humanos , Interleucina-6 , Modelos Estatísticos , Alta do Paciente , Segurança do Paciente , Prognóstico , Estudos Prospectivos , Receptores de Ativador de Plasminogênio Tipo Uroquinase , Reprodutibilidade dos Testes , SARS-CoV-2
4.
J Wound Care ; 31(2): 130-138, 2022 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-35148628

RESUMO

BACKGROUND: Soft tissue defects of the plantar foot pose a challenge to the reconstructive surgeon. The plantar region of the foot has a unique skin structure, which helps in its paramount functions of weight-bearing and providing protective sensation. It is best replaced with tissue of its own kind. The medial plantar artery (MPA) flap fulfils all the requirements of an ideal replacement for small-to-medium-sized defects in the mid plantar and heel region. This study describes our experience with MPA-based flaps for small-to-medium-sized defects of the plantar foot. METHOD: The study was conducted in a tertiary referral hospital between April 2017 and March 2020 on patients who presented with defects on the mid plantar region and heel. MPA perforator (MPAP) flap or island flap were applied. The donor site was covered with split-thickness skin grafts. RESULTS: The study included 21 patients. MPAP flap was applied in nine patients and the island flap was applied in 12 patients. The mean age of the patients was 37.95 years and the mean flap size was 36.6cm2. All flaps survived well. In two patients, venous congestion developed which resolved spontaneously, while three patients had small graft loss which also healed with conservative treatment. All patients regained protective sensation within five months of flap coverage. CONCLUSION: Based on the MPA, both perforator and island flaps can be raised due to the fairly constant position of the perforators. These flaps have the advantage of robust vascularity with the replacement of identical tissue for weight-bearing functions along with acceptable aesthetic outcomes. Since they also have the added advantage of conferring sensation, they can be used as a primary option in cases of small-to-medium-sized plantar foot defects.


Assuntos
Retalho Perfurante , Procedimentos de Cirurgia Plástica , Lesões dos Tecidos Moles , Adulto , Pé/cirurgia , Humanos , Transplante de Pele , Lesões dos Tecidos Moles/cirurgia , Retalhos Cirúrgicos , Artérias da Tíbia
5.
Indian J Crit Care Med ; 25(4): 463-464, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34045815

RESUMO

Severe acute respiratory syndrome coronavirus 2 is the pathogen that causes coronavirus disease-2019 (COVID-19). Recent studies have shown that the "cytokine storm" (high concentration of proinflammatory cytokines) may contribute to the mortality of COVID-19. Repeated exposure to the virus can lead to a dose-dependent immune response that may be associated with more disease severity and higher mortality. Sudden deterioration/increased oxygen consumption after initial improvement may be due to multiple surges of cytokines storm within a short period, the possible cause may be due to multiple exposures within the incubation period. We hypothesize that multiple surges in cytokines storm in some patients may be due to multiple exposures of the same patient within the incubation period, sepsis, or other inflammatory lesions inside the body. In our cases, sepsis as a cause of cytokine storm was ruled out by doing the procalcitonin test, which was within the normal limit. HOW TO CITE THIS ARTICLE: Kumar A, Kumar A, Kumar A, Kumar N, Sinha C, Singh V. Multiple Peaked Cytokine Storm: Is Multiple Exposures to the COVID-19 Virus a Possible Cause? Indian J Crit Care Med 2021;25(4):463-464.

6.
Indian J Crit Care Med ; 25(8): 948-949, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34733041

RESUMO

Oxygen supplementation is required for approximately 14% of the patients diagnosed of having COVID-19 infection. Despite the use of conventional oxygen therapy, 5% among these require treatment in the intensive care unit (ICU). Here, we are describing a situation in which oxygen therapy was delivered to the patients by making an assembly of oxygen tubing, three-way stopcock, and high-flow nasal cannula (HFNC) present in the hospital setting following the malfunction of air blender of HFNC machine (Fig. 1). This assembly might be useful as rescue oxygen therapy during a malfunction of HFNC machine and in resource-limited settings where HFNC machine is not available. The mechanisms of action could be (1) washout of anatomic dead space due to medium oxygen flow, (2) improved gas mixing in large airways, and (3) increased oxygen concentration inside the conducting airway. How to cite this article: Kumar A, Kumar A, Kumar N, Kumar A, Singh V, Kumar S, et al. Repackaging of Malfunctioning High-flow Nasal Cannula as a Rescue Oxygen Therapy: An Innovation amid COVID-19 Crisis. Indian J Crit Care Med 2021;25(8):948-949.

7.
Indian J Crit Care Med ; 25(10): 1113-1119, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34916742

RESUMO

BACKGROUND: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection affects the cardiovascular system at many levels. It initially infects endothelial cells, inducing marked endothelial damage and inflammation. However, there was no empirical evidence of functional compromise of arterial walls. AIMS AND OBJECTIVE: Our primary objective was to study functional arterial damage in coronavirus disease 2019 (COVID-19) and establish the noninvasive measurement of arterial stiffness as an independent marker of disease severity. MATERIALS AND METHODS: We recorded the arterial stiffness of 23 mild, 21 moderate, and 20 severe COVID-19 patients grouped on the latest National Institute of Health (NIH) severity criteria. We observed arterial stiffness of COVID-19 patients with standard parameters like noninvasive estimated carotid-femoral pulse wave velocity (cfPWV), age-normalized increase in cfPWV (ANI_cfPWV), age-normalized increase in aortic augmentation pressure (ANI_AugP), and heart rate-normalized augmentation index (HRN_ AIx). All the parameters were also corrected for statistically significant confounding factors. RESULTS: Moderate and severe COVID-19 patients have extremely significantly elevated arterial stiffness than mild patients. In mild patients, cfPWV (829.1 ± 139.2 cm/second) was significantly lower than both moderate (1067 ± 152.5 cm/second, p <0.0001) and severe (1416 ± 253.9 cm/second, p <0.0001) patients. ANI_cfPWV in moderate and severe patients was significantly higher than mild patients (mild: 101.2 ± 126.1 cm/second; moderate: 279 ± 114.4 cm/second; severe: 580.1 ± 216.4 cm/second; intergroup p <0.0001). The results even after correction for significant confounding factors did not show any considerable change in the increasing trend of arterial stiffness. CONCLUSION: This study establishes the functional deterioration of arteries in proportion to the severity of COVID-19. HOW TO CITE THIS ARTICLE: Kumar N, Kumar S, Kumar A, Bhushan D, Kumar A, Kumar A, et al. The COSEVAST Study Outcome: Evidence of COVID-19 Severity Proportionate to Surge in Arterial Stiffness. Indian J Crit Care Med 2021;25(10):1113-1119.

8.
J Emerg Med ; 59(6): e209-e212, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32917446

RESUMO

BACKGROUND: Candlenuts (Aleurites moluccana) and yellow oleander seeds (Thevetia peruviana) bear a physical resemblance to one another. Candlenuts are benign and marketed as weight loss supplements. Yellow oleander seeds, however, contain toxic cardioactive steroids; as few as 2 seeds may cause fatal poisoning. Because of their physical similarities, the potential for a lethal substitution exists. CASE REPORT: A 63-year-old woman presented to the emergency department with vomiting after ingesting 5 of what she believed to be candlenuts that were ordered online under the colloquial name "Nuez de la India" for the purpose of weight loss. She was bradycardic (nadir pulse of 30 beats/min) and hyperkalemic (serum potassium 7.3 mEq/L). Within hours of presentation she suffered a ventricular fibrillation arrest, followed by a terminal asystolic arrest. Postmortem analyses of liver tissue and the seeds were consistent with fatal T. peruviana poisoning. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: T. peruviana seeds contain toxic cardioactive steroids; their physical resemblance to candlenuts poses a risk of potentially fatal substitution. Therapy with high-dose digoxin specific immune fragments (20-30 vials) may be helpful.


Assuntos
Nerium , Intoxicação por Plantas , Ingestão de Alimentos , Feminino , Humanos , Índia , Pessoa de Meia-Idade , Intoxicação por Plantas/diagnóstico , Redução de Peso
9.
Opt Lett ; 41(7): 1554-7, 2016 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-27192285

RESUMO

In this Letter, we demonstrate quantitative phase imaging of biological samples, such as human red blood cells (RBCs) and onion cells using narrow temporal frequency and wide angular frequency spectrum light source. This type of light source was synthesized by the combined effect of spatial, angular, and temporal diversity of speckle reduction technique. The importance of using low spatial and high temporal coherence light source over the broad band and narrow band light source is that it does not require any dispersion compensation mechanism for biological samples. Further, it avoids the formation of speckle or spurious fringes which arises while using narrow band light source.


Assuntos
Eritrócitos , Processamento de Imagem Assistida por Computador , Humanos , Luz
10.
Appl Opt ; 55(10): 2521-5, 2016 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-27139652

RESUMO

We report multispectral phase-shifting interference microscopy for quantitative phase imaging of human red blood cells (RBCs). A wide range of wavelengths are covered by means of using multiple color light emitting diodes (LEDs) with narrow spectral bandwidth ranging from violet to deep red color. The multicolor LED light source was designed and operated sequentially, which works as a multispectral scanning light source. Corresponding to each color LED source, five phase-shifted interferograms were recorded sequentially for the measurement of phase maps, as well as the refractive index of RBCs within the entire visible region. The proposed technique provides information about the effect of wavelengths on the morphology and refractive index of human RBCs. The system does not require expensive multiple color filters or any wavelength scanning mechanism along with broadband light source.


Assuntos
Eritrócitos , Microscopia de Contraste de Fase , Cor , Humanos , Luz
11.
Clin Lab ; 60(6): 969-72, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25016702

RESUMO

BACKGROUND: Thyroid disorders especially hypothyroidism is associated with increased generation of oxidants. Nitric oxide and ischemia modified albumin are considered markers for oxidative stress. In addition, nitric oxide is involved in regulation of thyroid function and coagulation profile alteration in thyroid disorders may produce ischemia like conditions. METHODS: Nitric oxide and ischemia modified albumin were estimated in fifty patients of newly diagnosed hypothyroidism using standard photocolorimetric techniques. Results were compared with fifty healthy euthyroid controls and subjected to appropriate statistical analysis. RESULTS: Nitric oxide and ischemia modified albumin were found to be significantly raised (p < 0.05) in hypothyroid patients as compared to controls. A positive, but statistically insignificant correlation was observed between nitric oxide and ischemia modified albumin. CONCLUSIONS: Estmation of nitric oxide and ischemia modified albumin in hypothyroidism may help to throw light on its pathogenesis and assessing the severity of the disease, though further research is needed to establish their role as biomarkers in hypothyroidism.


Assuntos
Hipotireoidismo/sangue , Óxido Nítrico/sangue , Adulto , Biomarcadores/sangue , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estresse Oxidativo , Valores de Referência , Albumina Sérica , Albumina Sérica Humana , Estatísticas não Paramétricas , Adulto Jovem
12.
Surg J (N Y) ; 10(1): e1-e10, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38528856

RESUMO

Aim of the Study Mucormycosis is a rare invasive and fatal fungal infection and its resurgence in coronavirus disease 2019 (COVID-19) patients has been a matter of grave concern. It is essentially a medical disease, but surgical debridement of necrotic tissues is of paramount importance leading to severe craniofacial deformities. In this case series, we present our experience with the feasibility of early reconstruction after surgical debridement. Case Series As a Dedicated COVID Center (DCH), the institute received the largest population of COVID-19 mucormycosis patients from the entire eastern region of the country between May 2021 and August 2021. More than 5,000 COVID-19 were admitted out of which 218 patients were diagnosed with mucormycosis. Nine patients, seven males and two females, with a mean age of 39 years with craniofacial mucormycosis underwent debridement and early reconstructions (2-4 weeks from first debridement and start of antifungal therapy) with free and pedicled flaps. All flaps survived and showed no evidence of recurrence. The average time of the early reconstruction after surgical debridement was 1.7 weeks once the course of systemic amphotericin B was received. Conclusion After aggressive surgical resection and a short course of antifungal therapy, early reconstruction can be done safely based on clinical criteria, as long as there is no evidence of hyphae invasion on wound edges in the intraoperative pathology examination.

13.
Med Sci Educ ; 34(4): 865-871, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39099861

RESUMO

Purpose: This study explores the current knowledge and overall awareness of the faculty at an Apex institute about the use and difficulties of scenario-based multiple-choice questions (SB-MCQs), short-answer questions (SB-SAQs), and modified essay questions (SB-MEQs) in the assessment of the undergraduate and postgraduate students. Objectives: To assess faculty perception of awareness and use of SB-MCQs, SB-SAQs, and SB-MEQs and to understand the challenges encountered while designing scenario-based questions (SBQs) and the ways to overcome them. Study Procedure: The tool used for data collection was a Google form questionnaire designed with a total of 16 questions-12 Likert-scale format items and four open-ended questions. The quantitative data collected as a response to close-ended questions was analyzed by descriptive statistics and percentage values. For qualitative data, thematic analysis was done for open-ended questions. Conclusion: The study showed that the faculty has the motivation and agreeability to switch over from traditional questions to scenario-based questions but constant training in the form of regular faculty development programs and workshops is required for its effective implementation. On the administrative level, challenges like lack of sufficient faculty and proper inter-departmental integration for designing scenarios must be addressed. Supplementary Information: The online version contains supplementary material available at 10.1007/s40670-024-02052-6.

14.
J Hand Microsurg ; 16(1): 100022, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38854385

RESUMO

Free flaps are considered the gold standard for the reconstruction of various defects. Microvascular anastomosis is a very critical component of free flap surgery determining its success. The workhorse technique of hand suturing for microvascular anastomosis has consistently been used with excellent results. Recently, venous couplers are being increasingly used for performing venous anastomosis. We describe the case of a 14-year-old girl in which heel reconstruction was planned for an unstable scar and chronic osteomyelitis of the calcaneal region with a free latissimus dorsi muscle flap. Arterial anastomosis was done by hand suturing, while venous coupler (GEM coupler, Synovis Micro Companies Alliance) was used for venous anastomosis. Just before wound closure, the venous coupler spontaneously snapped open, resulting in disruption of the device and opening of the anastomosis. After securing hemostasis, the ring of the coupling device was tried to be removed, but it was adhered to the tunica externa due to the interlocking pins. Cutting the veins proximal to the rings would result in shortening of the vein with the requirement of a vein graft. The harvested latissimus dorsi muscle had a single vena comitans which had to be salvaged, so we improvised by everting the vein edges from the interlocking pins and completing the anastomosis by hand after freshening the margins. The interlocking rings were left as such in their place. Postoperative period was uneventful, and the flap survived with good results. Thus, this is a unique case where we report for the first time the disruption of a venous coupling device and subsequent salvage of free flap.

15.
Cureus ; 16(1): e52875, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38406071

RESUMO

A pseudoaneurysm is a collection of blood outside the arterial lumen but remains in continuity with the lumen and lined by fibrous tissue. Radial artery pseudoaneurysm is a rare entity mostly occurring due to iatrogenic reasons. Traumatic causes are rare. In this case report, we report a post-traumatic left radial artery pseudoaneurysm at the wrist level in a 20-year-old male patient. The patient was treated with end-to-end repair of excised pseudoaneurysm with a vein graft taken from the radial artery vena comitantes through the same incision.

16.
World Neurosurg ; 2024 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-39004182

RESUMO

BACKGROUND: Conventionally, neural transfer of the spinal accessory nerve to the suprascapular nerve for shoulder abduction in traumatic brachial plexus injury is performed via the anterior approach. However, important advantages of the posterior approach have made it an alternative option, such as the proximity of neural coaptation to the muscle to be reinnervated and negating the effects of a second injury to the suprascapular nerve. METHODS: Retrospective data was collected from 30 patients with brachial plexus injury who underwent spinal accessory nerve to suprascapular nerve transfer over 4 years. There were 15 patients in the anterior-approach group (group A) and 15 in the posterior-approach group (group B). Functional outcome at the shoulder was measured as muscle power and active range of motion at 18 months, and data on patients' satisfaction levels and surgeons' perceptions was also collected. RESULTS: No statistical difference was found in the muscle strength achieved in the 2 groups (P = 0.34), but significant recovery was found in the external rotation achieved by group B (P = 0.02). Statistical difference was insignificant in the 2 groups' active range of motion during abduction and external rotation. The satisfaction index of patients was 86.7% in group B as compared to 68% in group A. Surgeons' perspective showed a faster speed of suprascapular nerve exploration in the posterior approach, with better visibility of supraspinatus muscle contraction, and overall surgeons preferred the posterior approach. CONCLUSIONS: External rotation at the shoulder is better via the posterior approach, but no difference in abduction was noted. Patients who underwent the posterior approach were more satisfied with the recovery, and surgeons preferred the posterior approach.

17.
J Nanosci Nanotechnol ; 13(7): 5028-33, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23901526

RESUMO

The primary challenge in developing nanoparticle based enzymatic devices is to be able to chemically immobilize an enzyme, which will retain its activity or improve its function while being attached to the nanoparticle. This would be of even greater significance if the whole process could be performed under benign conditions without having to resort to functionalization of key molecules at various steps. In the present study the conjugates of amylase and silver nanoparticles were synthesized using neem leaf extract as the reducing and stabilizing agent. The silver nanoparticles were characterized using Surface Plasmon Resonance Spectra, Dynamic Light Spectroscopy (DLS), Fourier Transform Infrared Spectroscopy (FTIR), Circular Dichroism (CD) and Surface Tunneling Microscopy (STM). The silver nanoparticles retained 85% amylase activity. The nanobiocatalyst was further characterized in terms of kinetic parameters and thermal stability. It was thermally more stable as compared to the free alpha amylase enzyme.


Assuntos
Nanopartículas Metálicas/química , Folhas de Planta/química , Prata/química , alfa-Amilases/química , Ativação Enzimática , Substâncias Macromoleculares/química , Teste de Materiais , Conformação Molecular , Tamanho da Partícula , Propriedades de Superfície
18.
Ann Diagn Pathol ; 17(4): 322-6, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23660273

RESUMO

Molecular studies are part of standard care for cancer patients. Bone, a common and sometimes sole site of metastasis, requires decalcification for morphological examination. Many commonly used decalcification agents contain strong acids that degrade nucleic acids. The paradigm shift in oncology, with biomarker targeted therapy and gene expression profiling analysis, requires sufficient nucleic acid recovery from bone biopsy specimens. We systematically studied the effects of a spectrum of decalcification agents on the quantity and quality of RNA and DNA recovered from bone biopsies. Multiple bone biopsies of similar size and cellularity were fixed in 10% neutral-buffered formalin, randomized to various decalcification agents for 2 hours then processed, and embedded. Tissue lysates were obtained from unstained sections and nucleic acid isolated. DNA and RNA were quantified. Assessment of DNA and RNA integrity was accomplished by comparison of the average cycle threshold by polymerase chain reaction of selected housekeeping genes for each agent. Results were then analyzed by 2-sample t test. There was a significant decrease in both DNA and RNA yield and integrity with strong acids (hydrochloric, nitric) vs 14% EDTA and formic acid. DNA yield was (mean nanograms) 6.15 vs 68.68 (P<.001) and RNA was (mean nanograms) 121.53 vs 288.89 (P=.003), respectively. DNA integrity (mean cycle threshold) was 35.79 vs 30.16 (P<.001), and RNA was 33.03 vs 26.5 (P<.001), respectively. Decalcification of bone biopsies with EDTA or formic acid agents was associated with a significant improvement in recovered nucleic acid quantity and quality.


Assuntos
Osso e Ossos/efeitos dos fármacos , DNA/efeitos dos fármacos , Ácido Edético/farmacologia , Formiatos/farmacologia , RNA/efeitos dos fármacos , Adulto , Biópsia , DNA/análise , DNA/isolamento & purificação , Técnica de Descalcificação , Formaldeído , Humanos , Masculino , Pessoa de Meia-Idade , Inclusão em Parafina , RNA/análise , RNA/isolamento & purificação , Reação em Cadeia da Polimerase em Tempo Real , Fixação de Tecidos
20.
Materials (Basel) ; 16(4)2023 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-36837318

RESUMO

We report the fabrication and characterization of solution-route CeO2 thin films with a tunable porosity and microstructure. Films were deposited by means of inkjet printing technique using 0.2 M, 0.4 M and 0.6 M concentration inks prepared from Ce(NO3)3·6H2O precursor. Printing was performed at two different temperatures of 60 °C and 300 °C to study the variation in structure. Printing parameters were adjusted for the consecutive deposition of layers, resulting in ≈140 nm and ≈185 nm thick single layers for 60 °C and 300 °C printing temperatures, respectively. We compared the microstructure of printed films for different concentrations, printing temperatures, solvents and substrates. The formation of the cubic fluorite structure of the printed films was confirmed via XRD characterization. We suggest this technique as an advanced method for high-quality film fabrication with a controlled microstructure and with a minimal waste of materials. Through adjusting printing parameters, both dense and porous films can be produced for use in different applications.

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