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1.
Antimicrob Agents Chemother ; : e0050023, 2023 06 14.
Artículo en Inglés | MEDLINE | ID: mdl-37314343

RESUMEN

With limited and often toxic treatment options, carbapenem-resistant Gram-negative infections are associated with significant mortality. Cefepime-zidebactam is a promising antibiotic option undergoing a phase 3 trial that has activity against diverse antibiotic-resistant mechanisms in Gram-negative pathogens due to its ß-lactam enhancer mechanism, mediating multiple PBP binding. We report a case of disseminated infection caused by a New Delhi metallo-ß-lactamase-producing, extensively drug-resistant Pseudomonas aeruginosa isolate in a patient with acute T-cell leukemia, successfully managed with cefepime-zidebactam as a salvage therapy.


Asunto(s)
Leucemia-Linfoma Linfoblástico de Células T Precursoras , Infecciones por Pseudomonas , Adulto , Humanos , Pseudomonas aeruginosa/metabolismo , Infecciones por Pseudomonas/tratamiento farmacológico , Terapia Recuperativa , Cefalosporinas/uso terapéutico , Antibacterianos/uso terapéutico , beta-Lactamasas/genética , beta-Lactamasas/metabolismo , Compuestos de Azabiciclo/uso terapéutico , Pruebas de Sensibilidad Microbiana
2.
Appl Opt ; 62(25): 6802-6808, 2023 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-37706814

RESUMEN

The Satellite-Internet of Things (S-IoT) is envisaged as one of the promising technological enhancements in this decade due to its outright connectivity, especially in the areas of terrestrial communication and weather forecasting. Invariably, turbulent atmospheric conditions and varied terrain profiles are hindrances for satellite based free-space optical (FSO) communication, and immensely disrupt signal levels. Recently, a new technological invention called a reconfigurable intelligent surface (RIS) empowered radio transmission environments for next generation wireless/optical technology has emerged. Elements of RIS are used to intelligently tune the striking beam towards desired locations. In this paper, we propose an RIS based FSO link to manueuver S-IoT. The challenges of pointing errors and turbulent atmospheric connectivity from a satellite to ground station and vice versa with the cooperation of RIS have been derived and substantiated with closed form solutions. The proposed system's performance has been analyzed using packet and bit error rates, and outage probability over atmospheric turbulence, pointing errors, and signal blockage scenarios. Results are evaluated for different RIS elements as a function of average signal to noise ratio. The proposed system is extremely productive, since this scheme has the capability to provide dependable connectivity in rural, urban, and suburban environments where reliable connectivity is difficult in spite of traditional infrastructures.

3.
Appl Opt ; 62(31): 8366-8373, 2023 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-38037941

RESUMEN

This paper contemplates a relay-assisted visible light communication (VLC) system, where the light source (table lamp) acts as a relay node and cooperates with the main light source. Following the IEEE 802.15.7r1 VLC reference channel model, we assume that there are two different light sources present in an office room. The first one is the source terminal present on the ceiling and another one is the desk lamp that serves as the relay station, which works in a full-duplex method. Because of the loop interference channel, we model the VLC relay terminal using ray tracing simulations. We have analyzed the bit error rate (BER) performance of the relay-assisted VLC system using a binary phase shift keying-subcarrier intensity modulation (BPSK-SIM) technique. The proposed method outperforms existing phase shift keying (PSK) and square M-quadrature amplitude modulation (M-QAM) techniques. The proposed VLC system using the BPSK-SIM technique achieves a BER performance of 10-12 for an SNR of 20 dB. The results of the proposed full-duplex and half-duplex relayed VLC systems are evaluated using equal power allocation (EPA) and optimum power allocation (OPA) techniques over three different modulation schemes, which are 2-PSK, square M-QAM, and BPSK-SIM.

4.
Appl Opt ; 61(11): 3141-3149, 2022 Apr 10.
Artículo en Inglés | MEDLINE | ID: mdl-35471290

RESUMEN

Changes in the environment, such as landslides, tsunamis, rising or falling sea levels in coastal oceans, and neighboring land surfaces, significantly impact the structure of the ocean and human life. These natural climate-change processes have unanticipated and deadly consequences for coastal areas. The continental margin part of the ocean has recently attracted the most attention because of the mineral sources and human activities such as exploration, navigation, recreation, and fishing. The continental margin stretches from the coastal mountains and plains to continental shelf, slope, and rise, where terrestrial and maritime means meet. In this paper, we propose a reconfigurable underwater optical wireless sensor network (UOWSN) based on underwater wireless optical communication (UWOC) to monitor and discover continental margin ore deposits. In this proposed system, a transceiver on the underwater wireless autonomous vehicle moving around the different regions of the continental margin collects information and transmits it to the seashore control station once it reaches the ocean surface. We investigated the outage probability and average bit error rate of the proposed system at the continental margin and used coding techniques to mitigate the effects of high turbulence in the continental shelf region.

5.
Cluster Comput ; : 1-13, 2022 Aug 23.
Artículo en Inglés | MEDLINE | ID: mdl-36034677

RESUMEN

Patient health record analysis models assist the medical field to understand the current stands and medical needs. Similarly, collecting and analyzing the disease features are the best practice for encouraging medical researchers to understand the research problems. Various research works evolve the way of medical data analysis schemes to know the actual challenges against the diseases. The computer-based diagnosis models and medical data analysis models are widely applied to have a better understanding of different diseases. Particularly, the field of medical electronics needs appropriate health indicator extraction models in near future. The existing medical schemes support baseline solutions but lack optimal hypothesis-based solutions. This work describes the optimal hypothesis model and Akin procedures for health record users, to aid health sectors in clinical decision-making on health indications. This work proposes Medical Hypothesis and Health Indicators Extraction from Electronic Medical Records (EMR) and International Classification of Diseases (ICD-10) patient examination database using the Akin Method and Friendship method. In this Health Indicators and Disease Symptoms Extraction (HIDSE), the evidence checking procedures find and collect all possible medical evidence from the existing patient examination report. Akin Method is making the hypothesis decision from count-based evidence principles. The health indicators extraction scheme extracts all relevant information based on the health indicators query and partial input. Similarly, the friendship method is used for making information associations between medical data attributes. This Akin-Friendship model helps to build hypothesis structures and trait-based feature extraction principles. This is called as Composite Akin Friendship Model (CAFM). This proposed model consists of various test cases for developing the medical hypothesis systems. On the other hand, it provides limited accuracy in disease classification. In this regard, the proposed HIDSE implements Deep Learning (DL) based Akin Friendship Method (DLAFM) for improving the accuracy of this medical hypothesis model. The proposed DLAFM, Convolutional Neural Networks (CNN) associated Legacy Prediction Model for Health Indicator (LPHI) is developed to tune the CAFM principles. The results show the proposed health indicator extraction scheme has 8-10% of better system performance than other existing techniques.

6.
J Anaesthesiol Clin Pharmacol ; 38(4): 640-645, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36778836

RESUMEN

Background and Aims: The reliability of end tidal carbon dioxide (ETCO2) as a measure of arterial carbon dioxide (PaCO2) in pediatric laparoscopy is unclear. We evaluated the correlation of arterial to end tidal P(a-ET) CO2 during pediatric laparoscopy at two hours of pneumoperitoneum as the primary objective. We also compared P(a-ET) CO2 and alveolar to arterial oxygen gradient P(A-a) O2 and haemodynamics at fixed time points during surgery. Material and Methods: A cross-sectional study was conducted in 25 children undergoing laparoscopic abdominal surgery. Arterial blood gases were drawn at T0, baseline, T10: ten minutes, T1h: 1 hour, T2h: 2 hours of pnuemoperitoneum and T 10d: 10 mins after deflation. The P(a-ET) CO2, P(A-a) O2, were measured from the blood gas and ETCO2 and FiO2 values on the monitor. The Pearson's correlation coefficient, the Wilcoxon rank test and Chi square test were used for statistical analysis. Results: At T2h moderate correlation of P(a-ET) CO2 (r = 0.605, P = 0.001) with 40% children documenting accurate P(a-ET) CO2, -1 to +1 mm Hg was seen. Moderate correlation was also seen at T0, T10, T 10d but poor correlation at T 1h. The P(A-a) O2 increased progressively with surgery and did not correlate with P(a-ET) CO2. Heart rate was stable, but systolic blood pressures at T 10 and diastolic at T10, T 1h, T 2h were higher than baseline. Conclusion: Moderate correlation was seen between PaCO2 and ETCO2 at 2 h of pnuemoperitoneum and at T0, T 10, and T 10d. P(A-a) O2 increased with surgery but did not correlate with P(a-ET) CO2.

7.
Biochem J ; 477(18): 3625-3643, 2020 09 30.
Artículo en Inglés | MEDLINE | ID: mdl-32893851

RESUMEN

Plasmodium falciparum, the human malaria parasite harbors a metastable proteome which is vulnerable to proteotoxic stress conditions encountered during its lifecycle. How parasite's chaperone machinery is able to maintain its aggregation-prone proteome in functional state, is poorly understood. As HSP70-40 system forms the central hub in cellular proteostasis, we investigated the protein folding capacity of PfHSP70-1 and PfHSP40 chaperone pair and compared it with human orthologs (HSPA1A and DNAJA1). Despite the structural similarity, we observed that parasite chaperones and their human orthologs exhibit striking differences in conformational dynamics. Comprehensive biochemical investigations revealed that PfHSP70-1 and PfHSP40 chaperone pair has better protein folding, aggregation inhibition, oligomer remodeling and disaggregase activities than their human orthologs. Chaperone-swapping experiments suggest that PfHSP40 can also efficiently cooperate with human HSP70 to facilitate the folding of client-substrate. SPR-derived kinetic parameters reveal that PfHSP40 has higher binding affinity towards unfolded substrate than DNAJA1. Interestingly, the observed slow dissociation rate of PfHSP40-substrate interaction allows PfHSP40 to maintain the substrate in folding-competent state to minimize its misfolding. Structural investigation through small angle x-ray scattering gave insights into the conformational architecture of PfHSP70-1 (monomer), PfHSP40 (dimer) and their complex. Overall, our data suggest that the parasite has evolved functionally diverged and efficient chaperone machinery which allows the human malaria parasite to survive in hostile conditions. The distinct allosteric landscapes and interaction kinetics of plasmodial chaperones open avenues for the exploration of small-molecule based antimalarial interventions.


Asunto(s)
Proteínas del Choque Térmico HSP40/química , Proteínas del Choque Térmico HSP72/química , Plasmodium falciparum/química , Pliegue de Proteína , Proteínas Protozoarias/química , Proteínas del Choque Térmico HSP40/genética , Proteínas del Choque Térmico HSP40/metabolismo , Proteínas del Choque Térmico HSP72/genética , Proteínas del Choque Térmico HSP72/metabolismo , Humanos , Plasmodium falciparum/genética , Plasmodium falciparum/metabolismo , Proteínas Protozoarias/genética , Proteínas Protozoarias/metabolismo
8.
Sensors (Basel) ; 20(23)2020 Nov 29.
Artículo en Inglés | MEDLINE | ID: mdl-33260295

RESUMEN

The electrical machine core is subjected to mechanical stresses during manufacturing processes. These stresses include radial, circumferential and axial components that may have significant influence on the magnetic properties and it further leads to increase in iron loss and permeability in the stator core. In this research work, analysis of magnetic core iron loss under axial mechanical stress is investigated. The magnetic core is designed with Magnetic Flux Density (MF) ranging from 1.0 T to 1.5 T with estimated dimensions under various input voltages from 5 V to 85 V. Iron losses are predicted by the axial pressure created manually wherever required and is further applied to the designed magnetic core in the range of 5 MPa to 50 MPa. Finite element analysis is employed to estimate the magnetic core parameters and the magnetic core dimensions. A ring core is designed with the selected dimensions for the experimental evaluation. The analysis of iron loss at 50Hz frequency for non-oriented electrical steel of M400-50A is tested experimentally using the Epstein frame test and force-fit setup test. Experimental evaluation concludes that the magnetic core saturates when it reaches its knee point of the B-H curve of the chosen material and also reveals that the axial pressure has a high impact on the magnetic properties of the material.

9.
Ir Med J ; 3(112): 902, 2019 03 14.
Artículo en Inglés | MEDLINE | ID: mdl-31124350

RESUMEN

Aim To report the first case of cardiac tamponade related to Infliximab induction therapy in an Ulcerative Colitis patient. Methods Review of published case reports. Results This complication was likely due to a type 3 hypersensitivity immune-complex reaction resulting in a reactive pericardial effusion Discussion Though rare, this case demonstrates how autoimmune reaction to anti-TNF𝛼 therapy can initially mimic infection, as our patient presented with tachycardia, hypotension, raised inflammatory and infective markers and fever.


Asunto(s)
Taponamiento Cardíaco/inducido químicamente , Colitis Ulcerosa/tratamiento farmacológico , Fármacos Gastrointestinales/efectos adversos , Infliximab/efectos adversos , Autoinmunidad , Taponamiento Cardíaco/diagnóstico , Taponamiento Cardíaco/inmunología , Taponamiento Cardíaco/terapia , Colitis Ulcerosa/inmunología , Femenino , Fármacos Gastrointestinales/administración & dosificación , Fármacos Gastrointestinales/inmunología , Humanos , Infliximab/administración & dosificación , Infliximab/inmunología , Persona de Mediana Edad , Derrame Pericárdico/inducido químicamente , Derrame Pericárdico/diagnóstico , Derrame Pericárdico/inmunología , Derrame Pericárdico/terapia , Resultado del Tratamiento , Factor de Necrosis Tumoral alfa/inmunología
10.
Org Biomol Chem ; 16(13): 2258-2263, 2018 03 28.
Artículo en Inglés | MEDLINE | ID: mdl-29528353

RESUMEN

An unprecedented approach for the assembly of thioureido peptidomimetics is developed employing alkyl azides and dithiocarbamates. Dithiocarbamates react with alkyl azides with the liberation of N2 and elemental sulfur thereby leading to thiourea in a traceless manner. Thioureido peptidomimetics are thus furnished in good yields with no epimerization. This process is mild, free from the use of a base, scalable and step economic. The practicability of this methodology has been highlighted by the synthesis of N,N'-orthogonally protected thioureido peptidomimetics.

11.
Org Biomol Chem ; 16(19): 3524-3552, 2018 05 15.
Artículo en Inglés | MEDLINE | ID: mdl-29676414

RESUMEN

The synthesis of α-amino thioacids and peptide thioacids and their applications in chemoselective amide bond formation, ligation of peptides/proteins/glycopeptides and synthesis of peptidomimetics are reviewed. A variety of successful methods including both C-terminal and N-terminal activations for the coupling of α-amino thioacids and peptide thioacids have ascertained the thioacid-based protocol as a benign alternative to some of the traditional methods of amide/peptide bond formation which employs carboxyl activation. In addition to the couplings involving unprotected peptide fragments and solid phase synthesis, their use in the synthesis of different classes of peptidomimetics such as thioxopeptides, imide conjugates and acylsulfonamide-peptide conjugates only illustrates the versatility of this functionality in generating diverse classes of molecules, some of which are relevant to drug discovery and chemical biology. A note on more reactive seleno counterparts of thioacids, which can be useful in selective cases, is provided.


Asunto(s)
Amidas/química , Péptidos/química , Péptidos/síntesis química , Peptidomiméticos/química , Peptidomiméticos/síntesis química , Azufre/química
12.
J Postgrad Med ; 64(2): 109-111, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29067925

RESUMEN

Cytogenetic anomalies involving the 3q26 chromosomal region are rare in acute myeloid leukemia (AML). There is no such description of these anomalies from the Indian sub-continent. A total of 174 AML patients were admitted to our hospital for therapy between January 2001 and January 2008. Cytogenetic studies could be done in 115 patients; which revealed three cases with 3q26 anomalies. All were males. In the first two cases, the anomaly was detected in all the metaphases. The common features seen were the presence of only mild thrombocytopenia (relatively high platelet counts when assessed against the background of AML with high blast percentages), monosomy 7, myeloperoxidase positive blasts, mild eosinophilia, and poor therapeutic response. In the third case, the chromosome 3 anomaly was present in only one metaphase. Such an anomaly has not been reported. Only the third patient responded to induction therapy but subsequently relapsed after being in complete remission for 15 months. 3q26 anomalies are associated with monosomy 7, relatively higher platelet counts at diagnosis as compared with other non-3q rearranged AML's and poor prognosis. The precise mechanisms underlying leukemogenesis need to be elucidated and better treatments devised since these patients respond poorly to therapy.


Asunto(s)
Aberraciones Cromosómicas , Cromosomas Humanos Par 3 , Leucemia Mieloide Aguda/genética , Translocación Genética , Citogenética , Humanos , Leucemia Mieloide Aguda/diagnóstico , Leucemia Mieloide Aguda/patología , Masculino
13.
Water Sci Technol ; 77(9-10): 2228-2241, 2018 May.
Artículo en Inglés | MEDLINE | ID: mdl-29757175

RESUMEN

This study used the technical, economic analysis tool, SuperPro designer in evaluating a novel technology for simultaneous production of extracellular polymeric substance (EPS) and biodiesel using crude glycerol and secondary sludge. As renewable energy sources are depleting, the process utilizes municipal sewage sludge for production of EPS and biodiesel along with crude glycerol, which is a waste byproduct of biodiesel industry providing an alternate way for disposal of municipal sludge and crude glycerol. Newly isolated Cloacibacterium normanense NK6 is used as micro-organism in the study as it is capable of producing high EPS concentration, using activated sludge and crude glycerol as the sole carbon source. The technology has many environmental and economic advantages like the simultaneous production of two major products: EPS and lipids. Sensitivity analysis of the process revealed that biomass lipid content is a most significant factor where unit cost production of biodiesel was highly sensitive to lipid content during bioreaction. B7 biodiesel unit production cost can be lowered from $1 to $0.6 if the lipid content of the biomass is improved by various process parameter modifications.


Asunto(s)
Flavobacteriaceae/metabolismo , Glicerol/metabolismo , Lípidos/biosíntesis , Polímeros/metabolismo , Aguas del Alcantarillado/química , Biocombustibles/economía , Biomasa , Reactores Biológicos , Carbono , Análisis Costo-Beneficio , Glicerol/química , Polímeros/química
14.
J Virol ; 90(23): 10600-10611, 2016 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-27654297

RESUMEN

Since the India and Indian Ocean outbreaks of 2005 and 2006, the global distribution of chikungunya virus (CHIKV) and the locations of epidemics have dramatically shifted. First, the Indian Ocean lineage (IOL) caused sustained epidemics in India and has radiated to many other countries. Second, the Asian lineage has caused frequent outbreaks in the Pacific islands and in 2013 was introduced into the Caribbean, followed by rapid spread to nearly all of the neotropics. Further, CHIKV epidemics, as well as exported cases, have been reported in central Africa after a long period of perceived silence. To understand these changes and to anticipate the future of the virus, the exact distribution, genetic diversity, transmission routes, and future epidemic potential of CHIKV require further assessment. To do so, we conducted the most comprehensive phylogenetic analysis to date, examined CHIKV evolution and transmission, and explored distinct genetic factors associated with the emergence of the East/Central/South African (ECSA) lineage, the IOL, and the Asian lineage. Our results reveal contrasting evolutionary patterns among the lineages, with growing genetic diversities observed in each, and suggest that CHIKV will continue to be a major public health threat with the potential for further emergence and spread. IMPORTANCE: Chikungunya fever is a reemerging infectious disease that is transmitted by Aedes mosquitoes and causes severe health and economic burdens in affected populations. Since the unprecedented Indian Ocean and Indian subcontinent outbreaks of 2005 and 2006, CHIKV has further expanded its geographic range, including to the Americas in 2013. Its evolution and transmission during and following these epidemics, as well as the recent evolution and spread of other lineages, require optimal assessment. Using newly obtained genome sequences, we provide a comprehensive update of the global distribution of CHIKV genetic diversity and analyze factors associated with recent outbreaks. These results provide a solid foundation for future evolutionary studies of CHIKV that can elucidate emergence mechanisms and also may help to predict future epidemics.


Asunto(s)
Fiebre Chikungunya/epidemiología , Fiebre Chikungunya/virología , Virus Chikungunya/clasificación , Virus Chikungunya/genética , Regiones no Traducidas 5' , Aedes/virología , África/epidemiología , Américas/epidemiología , Animales , Asia/epidemiología , Fiebre Chikungunya/transmisión , Epidemias , Evolución Molecular , Variación Genética , Genoma Viral , Humanos , India/epidemiología , Insectos Vectores/virología , Filogenia
15.
Eur J Clin Microbiol Infect Dis ; 36(9): 1635-1641, 2017 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-28401321

RESUMEN

The present study was carried out with the objectives of genotyping Pneumocystis jirovecii at three distinct loci, to identify the single nucleotide polymorphisms (SNPs), and to study its clinical implications in patients with Pneumocystis pneumonia (PCP). Analysis of genetic diversity in P. jirovecii from immunocompromised patients was carried out by genotyping at three distinct loci encoding mitochondrial large subunit rRNA (mtLSU rRNA), cytochrome b (CYB), and superoxide dismutase (SOD) using polymerase chain reaction (PCR) assays followed by direct DNA sequencing. Of the 300 patients enrolled in the present study, 31 (10.33%) were positive for PCP by a specific mtLSU rRNA nested PCR assay, whereas only 15 P. jirovecii could be amplified at the other two loci (SOD and CYB). These positives were further subjected to sequence typing. Important genotypic combinations between four SNPs (mt85, SOD110, SOD215, and CYB838) and clinical outcomes could be observed in the present study, and mt85A, mt85T, and SOD110C/SOD215T were frequently associated with "negative follow-up". These SNPs were also noted to be relatively more prevalent amongst circulating genotypes in our study population. The present study is the first of its kind from the Indian subcontinent and demonstrated that potential SNPs of P. jirovecii may possibly be attributed to the clinical outcome of PCP episodes in terms of severity or fatality in different susceptible populations likely to develop PCP during their course of illness.


Asunto(s)
Genotipo , Pneumocystis carinii/genética , Neumonía por Pneumocystis/epidemiología , Neumonía por Pneumocystis/microbiología , Adolescente , Adulto , Niño , Femenino , Genes de ARNr , Variación Genética , Humanos , India/epidemiología , Masculino , Persona de Mediana Edad , Tipificación Molecular , Pneumocystis carinii/clasificación , Neumonía por Pneumocystis/diagnóstico , Neumonía por Pneumocystis/tratamiento farmacológico , Polimorfismo de Nucleótido Simple , Adulto Joven
16.
Colorectal Dis ; 19(1): 45-49, 2017 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-27197580

RESUMEN

AIM: Chronic constipation can be aetiopathogenically classified into slow transit constipation (STC), rectal evacuation difficulty (RED) or a combination (BOTH). Although the efficacy of percutaneous tibial nerve stimulation (PTNS) in faecal incontinence has been well proved, a current literature search identifies only one study which assessed its effect on constipation. We aimed to evaluate the effectiveness of PTNS in patients with different causes of constipation. METHOD: Thirty-four patients [30 women, median age 50 (20-79) years] with constipation who had previously failed maximal laxative and biofeedback therapy participated in the study. All patients underwent a baseline radio-opaque marker transit study and anorectal physiology examination. All had 12 sessions of PTNS of 30 min per session. A fall in the Wexner constipation score to ≤15 or by ≥5 points was taken as the primary outcome. Secondary outcomes included the results of pre- and post- PTNS transit and anorectal physiology studies. RESULTS: Eleven patients had STC, 14 had RED and nine had BOTH. A response was seen in four patients (1/11 STC, 2/14 RED and 1/9 BOTH). Comparing pre- and post- PTNS, there was no significant change in the mean Wexner score (P = 0.10). There was no change in colonic transit time among the whole population (P = 0.56) or among those with STC (P = 0.47). There was no improvement in balloon expulsion in the whole group (P = 0.73) or in patients with RED (P = 0.69). CONCLUSION: PTNS is of no benefit to patients with constipation, whatever aetiopathogenic mechanism is responsible for the symptoms.


Asunto(s)
Estreñimiento/terapia , Nervio Tibial , Estimulación Eléctrica Transcutánea del Nervio/métodos , Adulto , Anciano , Estreñimiento/fisiopatología , Femenino , Tránsito Gastrointestinal , Humanos , Masculino , Persona de Mediana Edad , Recto/inervación , Índice de Severidad de la Enfermedad , Resultado del Tratamiento , Adulto Joven
17.
Appl Opt ; 56(24): 6902-6910, 2017 Aug 20.
Artículo en Inglés | MEDLINE | ID: mdl-29048033

RESUMEN

Evolution of acoustic shock wave (ASW) properties generated during nanosecond (ns) and picosecond (ps) laser-induced breakdown (LIB) of atmospheric air at different input intensities is presented. The intensity is varied by changing the focal geometry of ns and ps pulses. The ASW pressures are observed to follow the dynamic interplay between the plasma density and recombination of plasma species. The conversion of laser energy to acoustic energy has increased from loose to tight focusing conditions. The central frequencies have moved toward the lower side with increasing laser intensities for both ns-LIB (76-48 kHz) and ps-LIB (111.2-92.1 kHz). The angular distribution of acoustic emissions was observed to follow the laser-induced plasma spark in both ns- and ps-LIB.

18.
J Oral Maxillofac Surg ; 75(7): 1322-1329, 2017 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-28249808

RESUMEN

PURPOSE: This study investigated the potential of platelet-rich fibrin (PRF) for osseous regeneration and soft tissue healing in mandibular third molar impaction sockets. MATERIALS AND METHODS: A prospective in vivo study was performed. Randomization was performed after extraction. On one side, the socket was sutured primarily (control site); on the other side, autologous PRF gel was placed and then the socket was sutured (test site). Postoperatively, grid periapical radiographs were obtained at periodic intervals (weeks 1, 4, and 16) and digitalized. Gray-level values were measured at 3 different regions of the socket (for regions of newly formed bone) compared with the natural bone area using HL Image++ software, and the percentage bone fill was measured. Clinical evaluation of soft tissue healing was performed using the healing index of Landry et al (J Periodontol 60:212, 1994) at the specific intervals. RESULTS: Thirty healthy men and women (age range, 18 to 35 yr) with bilaterally impacted mandibular third molars were enrolled in this study. In general, there was markedly greater bone formation in sockets treated with PRF (P < .05). In the PRF group, the average gray-level values at the cervical, middle, and apical regions were 61.85 (standard deviation [SD], ±25.186), 64.54 (SD, ±24.831), and 67.80 (SD, ±23.946), respectively, with a mean value of 64.73 (SD, ±24.411). In the control group, these values were 51.58 (SD, ±15.286), 54.30 (SD, ±16.274), and 57.53 (SD, ±16.187), respectively, with a mean of 53.67 (SD, ±16.528). The average percentage of bone fill in the PRF group was 57.90 (SD, ±26.789) and that of the non-PRF group was 46.74 (SD, ±17.713; P < .05). Soft tissue healing as evaluated by the healing index of Landry et al also was found to be better at the PRF test site and it was statistically significant (P < .05). CONCLUSIONS: There was evidence for better osseous regeneration and soft tissue healing in response to PRF. Further investigations to evaluate the application of PRF in other areas of oral and maxillofacial surgery are imperative.


Asunto(s)
Regeneración Ósea , Adhesivo de Tejido de Fibrina , Tercer Molar/cirugía , Plasma Rico en Plaquetas , Alveolo Dental/cirugía , Diente Impactado/cirugía , Adolescente , Adulto , Femenino , Adhesivo de Tejido de Fibrina/administración & dosificación , Humanos , Masculino , Estudios Prospectivos , Adulto Joven
19.
Appl Opt ; 55(3): 548-55, 2016 Jan 20.
Artículo en Inglés | MEDLINE | ID: mdl-26835930

RESUMEN

Acoustic shock waves (ASWs) in the frequency range of 30-120 kHz generated during laser-induced breakdown (LIB) of ambient air using 7 ns and 30 ps pulse durations are studied. The specific frequency range and peak amplitudes are observed to be different for nanosecond (ns) and picosecond (ps) LIB. The ASW frequencies for ps-LIB lie between 90 and 120 kHz with one dominant peak, whereas for ns-LIB, two dominant peaks with frequencies in the 30-70 kHz and 80-120 kHz range are observed. These frequencies are observed to be laser pulse intensity dependent. With increasing energy of ns laser pulses, acoustic frequencies move toward the audible frequency range. The variation in the acoustic parameters, such as peak-to-peak pressures, signal energy, frequency and acoustic pulse widths as a function of laser energy, for two different pulse durations are presented in detail and compared. The acoustic emissions are observed to be higher for ns-LIB than ps-LIB, indicating higher conversion efficiency of optical energy into mechanical energy.

20.
Gen Dent ; 64(1): e10-1, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-26742177

RESUMEN

This article reviews the hemostatic properties of snake venoms and their potential clinical application.


Asunto(s)
Odontología/métodos , Hemostáticos/uso terapéutico , Venenos de Serpiente/uso terapéutico , Humanos
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