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1.
Sensors (Basel) ; 21(17)2021 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-34502865

RESUMO

Continuous authentication has been proposed as a possible approach for passive and seamless user authentication, using sensor data comprising biometric, behavioral, and context-oriented characteristics. Since these are personal data being transmitted and are outside the control of the user, this approach causes privacy issues. Continuous authentication has security challenges concerning poor matching rates and susceptibility of replay attacks. The security issues are mainly poor matching rates and the problems of replay attacks. In this survey, we present an overview of continuous authentication and comprehensively discusses its different modes, and issues that these modes have related to security, privacy, and usability. A comparison of privacy-preserving approaches dealing with the privacy issues is provided, and lastly recommendations for secure, privacy-preserving, and user-friendly continuous authentication.


Assuntos
Privacidade , Telemedicina , Biometria , Segurança Computacional , Confidencialidade
2.
Dis Colon Rectum ; 63(5): 646-654, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32032203

RESUMO

BACKGROUND: Diverticulitis is separated into complicated and uncomplicated, based on the patient's presentation at the time of his or her initial attack of acute diverticulitis. OBJECTIVE: The aim of this study was to identify risk factors for persistent complex diverticulitis, defined as an abscess, fistula, or stricture, at the time of elective surgery, and to characterize outcomes in this patient population. DESIGN: This was a retrospective review of 2010 to 2016 in the American College of Surgeons National Surgical Quality Improvement Project database. SETTINGS: Individuals diagnosed with diverticulitis who underwent elective surgery were included. PATIENTS: A total of 1502 patients underwent elective surgery for diverticulitis, of which 559 (37%) patients had a surgical indication of persistent complex diverticulitis. INTERVENTIONS: We performed logistic regression analysis to identify risk factors for complex diverticulitis and evaluated a new prediction model. MAIN OUTCOME MEASURES: The predictive factors of persistent complex diverticulitis for elective colon resection were measured. RESULTS: The patients with complex diverticulitis were older (p < 0.001), had worse functional status (p < 0.001), more comorbidities (diabetes mellitus and hypertension), and a higher Charlson Comorbidity Index (2.7 vs 1.6, p < 0.001). They were more likely to have a history of tobacco or alcohol use (p < 0.001) and to be malnourished. Interestingly, patients found to have persistent complex diverticulitis did not have more episodes than patients with uncomplicated cases did (p = 0.67). Surgical time was longer in complex diverticulitis, and the patients were more likely to require diverting stomas and concurrent resections of adjacent structures. The area under the curve from the test set was (0.75; 95% CI, 0.72-0.78), sensitivity and specificity were 0.890 (95% CI, 0.870-0.891) and 0.450 (95% CI, 0.410-0.490). LIMITATIONS: The study was limited by its retrospective review and observational bias. CONCLUSIONS: Patients undergoing elective surgery for complex diverticulitis did not have more episodes. Instead, complex diverticulitis may be a reflection of a complicated patient, suggesting that complicated patients should have a different algorithm of care at the time of their initial presentation with diverticulitis to prevent the development of complex disease. See Video Abstract at http://links.lww.com/DCR/B183. ¿PODEMOS PREDECIR DIVERTICULITIS QUIRÚRGICAMENTE COMPLEJA EN CASOS ELECTIVOS?: La diverticulitis se divide en complicada y sin complicaciones, según la presentación del paciente en el momento de su ataque inicial de diverticulitis aguda.El objetivo de este estudio fue identificar los factores de riesgo para la diverticulitis compleja persistente, definida como un absceso, fístula o estenosis, en el momento de la cirugía electiva, y caracterizar los resultados en esta población de pacientes.Esta fue una revisión retrospectiva del 2010-2016 en la base de datos del Proyecto de Mejora de la Calidad Quirúrgica Nacional del Colegio Estadounidense de Cirujanos.Se incluyeron individuos diagnosticados con diverticulitis que se sometieron a cirugía electiva.1502 pacientes fueron sometidos a cirugía electiva por diverticulitis, de los cuales 559 (37%) pacientes tenían una indicación quirúrgica de diverticulitis compleja persistente.Realizamos un análisis de regresión logística para identificar los factores de riesgo de diverticulitis compleja y evaluamos un nuevo modelo de predicción.Se midieron los factores predictivos de diverticulitis compleja persistente para la resección de colon electiva.Los pacientes con diverticulitis compleja eran mayores (p <0,001), tenían un peor estado funcional (p <0,001), más comorbilidades (diabetes e hipertensión) y un índice de comorbilidad de Charlson más alto (2,7 frente a 1,6, p <0,001). Tenían más probabilidades de tener antecedentes de consumo de tabaco o alcohol (p <0.001) y estar desnutridos. Curiosamente, los pacientes con diverticulitis compleja persistente no tuvieron más episodios que los pacientes sin complicaciones (p = 0,67). El tiempo quirúrgico fue más largo en la diverticulitis compleja y era más probable que requirieran estomas para desvio y resecciones concurrentes de estructuras adyacentes. El área bajo la curva de prueba fue (0.75, intervalo de confianza del 95% 0.72-0.78), la sensibilidad y la especificidad fueron 0.890 (intervalo de confianza del 95%; 0.870-0.891) y 0.450 (intervalo de confianza del 95%; 0.410-0.490), respectivamente.El estudio estuvo limitado por su revisión retrospectiva y sesgo observacional.Los pacientes sometidos a cirugía electiva por diverticulitis compleja no tuvieron más episodios. En cambio, la diverticulitis compleja puede ser un reflejo de un paciente complicado, lo que sugiere que los pacientes complicados deben tener un algoritmo de atención diferente al momento de su presentación inicial con diverticulitis para prevenir el desarrollo de una enfermedad compleja. Consulte Video Resumen en http://links.lww.com/DCR/B183. (Traducción-Dr. Yesenia Rojas-Kahlil).


Assuntos
Colectomia/efeitos adversos , Diverticulite/cirurgia , Procedimentos Cirúrgicos Eletivos/efeitos adversos , Complicações Pós-Operatórias/epidemiologia , Adulto , Idoso , Diverticulite/diagnóstico , Diverticulite/etiologia , Feminino , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Seleção de Pacientes , Valor Preditivo dos Testes , Estudos Retrospectivos , Fatores de Risco
3.
Fish Physiol Biochem ; 40(1): 75-81, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23801365

RESUMO

Effects of three prostaglandins (i.e., prostanoids) and one of its precursors, arachidonic acid, were examined on the melanophores of the fish Labeo rohita (Ham.). PGE1, PGE2, PGF(2α) and arachidonic acid elicit a concentration-related dispersion in the fish melanophores. In vitro analysis of melanophores was performed through incubation of the isolated fish scales in different agonists and antagonists solutions. Dispersal effect of prostanoids may be mediated directly through the typical receptors or indirectly through release of neurotransmitter substance(s) from the melanophore nerve endings. Denervation of fish melanophores rendered them insensitive to prostanoid (PGF(2α)). Propranolol and verapamil completely inhibited the dispersal effects of PGF(2α); theophylline and indomethacine blocked the effects of higher concentrations of PGF(2α). During dispersing influence of PGF(2α), a free flux of Ca²âº ions was required and the indirectly released substance(s) from melanophore nerve endings would be the catecholamines of adrenergic and purinergic in nature.


Assuntos
Carpas/metabolismo , Melanóforos/metabolismo , Pigmentação , Prostaglandinas/fisiologia , Animais , Antagonistas de Prostaglandina
4.
Cancer ; 118(14): 3549-55, 2012 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-22086552

RESUMO

BACKGROUND: High-dose chemotherapy with autologous hematopoietic cell transplant (auto-HCT) has been shown to improve survival in patients with newly diagnosed multiple myeloma. However, the role of salvage auto-HCT for relapsed patients, particularly in the era of novel therapeutics, is not well defined. METHODS: The authors performed a retrospective analysis of all 44 myeloma patients (24 men, 20 women) who received a second auto-HCT as salvage between January 3, 1992 and November 4, 2008 at The University of Texas MD Anderson Cancer Center. RESULTS: Median interval between the first and salvage auto-HCT was 30 months (range, 2-78 months). Median age at salvage HCT was 54 years (range, 38-73 years), and median number of salvage treatment regimens was 2 (range, 0-5). Eleven (25%) patients had high-risk chromosomal abnormalities on conventional cytogenetic studies between diagnosis and salvage auto-HCT. Ten patients (23%) experienced grade 3 or higher nonhematologic toxicity after the salvage auto-HCT. One patient died within 100 days, for a treatment-related mortality of 2%. Best responses after salvage chemotherapy + salvage auto-HCT were as follows: complete response (CR) + near CR, 11%; partial response, 79%; overall response rate, 90%. Eighteen (41%) patients received post auto-HCT maintenance therapy. Median follow-up from salvage HCT was 41 months. Kaplan-Meier estimates of median progression-free survival (PFS) and overall survival (OS) from time of salvage auto-HCT were 12.3 and 31.7 months, respectively. Median OS from the time of diagnosis was 75 months. In a fitted Bayesian multivariate model, shorter time to progression after first auto-HCT, greater number of prior therapies, African American race, and immunoglobulin G subtype were significantly associated with worse OS. CONCLUSIONS: In selected myeloma patients, a second auto-HCT for salvage therapy is well tolerated, with acceptable toxicity. The overall response rate and PFS are comparable to other salvage regimens.


Assuntos
Transplante de Células-Tronco Hematopoéticas , Mieloma Múltiplo/terapia , Adulto , Idoso , Intervalo Livre de Doença , Feminino , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Humanos , Masculino , Pessoa de Meia-Idade , Mieloma Múltiplo/patologia , Prognóstico , Recidiva , Indução de Remissão , Retratamento , Terapia de Salvação , Transplante Autólogo
5.
J Recept Signal Transduct Res ; 32(2): 114-9, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22404113

RESUMO

The hormone melatonin regulates the biological clock and assist in various other physiologies of vertebrates. Present work is intended to check the affinity of saccharin towards the melatonin receptors and the possible role of saccharin interference in the melatonin physiology. The present in vitro study is based on the working model of isolated scale melanophores in the dorso-lateral region of Labeo rohita. The pigment cells were incubated in the agonist and the antagonists within a limited time frame and subsequently their Melanophore Size Index (MSI) were calculated. The inferences were drafted through the observed signal transduction upshots in pigment translocations within the melanophores. Saccharin, in a wide dose range, has consistently induced a concentration-related aggregation similar to the aggregatory effect as shown by melatonin on the melanophores. Binding of saccharin with the receptors and eliciting its aggregatory effect is partially dependent on the release of neurotransmitters. The aggregatory effects were found to be significantly blocked by luzindole, K185, and prazosin, which are the potent melatonin receptor blockers, at the higher concentrations of saccharin. Hence, all the three subtypes of melatonin receptors viz. MT1, MT2, and MT3 are participating in saccharin-mediated aggregations. Blocking by neomycin shows that Ca²âº ions are very crucial in dispensing the aggregatory effect of the sweetener. This research demands that an intensive and careful thorough study should be made about saccharin, specifically its effects upon melatonin physiology, before its unwarranted use as the food ingredients for human use.


Assuntos
Melanóforos/metabolismo , Melatonina/metabolismo , Receptores de Melatonina/metabolismo , Sacarina/farmacologia , Edulcorantes/farmacologia , Antagonistas de Receptores Adrenérgicos alfa 1/farmacologia , Animais , Denervação , Peixes , Indóis/farmacologia , Prazosina/farmacologia , Receptores de Melatonina/antagonistas & inibidores , Transdução de Sinais , Triptaminas/farmacologia
6.
J Recept Signal Transduct Res ; 31(5): 381-6, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21929292

RESUMO

The present study was undertaken to ascertain whether the casein derived bitter tastant Cyclo (Leu-Trp) [CLT] has an affinity or not for the particular receptors of the pineal hormone, melatonin, on the melanophores of a major carp Labeo rohita (Ham.). The bitter tastant CLT, in the dose range of 3.34×10(-16) M to 3.34×10(-4) M, has induced an aggregatory effect but not in a dose dependent manner. Binding of CLT with the receptors may vary at different concentrations. Denervation of the melanophores has shown a complete inhibition of the CLT mediated aggregation. Prazosin has partially inhibited the aggregatory effect of CLT. Moreover, the bitter tastant's response is mediated through the α2 adrenoceptors only at particular dose ranges. The MT1 and MT2 melatonin receptor antagonist luzindole and the MT2 specific antagonist K185 have perfectly blocked the aggregatory effects of CLT. We have found that the CLT mediated aggregatory effect is dependent upon the release of neurotransmitters and the two subtypes of melatonin (MT) receptors (MT1 and MT2) possess a perfect affinity towards the bitter tastant CLT. Our study demands a need to further make a clinical research on the effects of bitter tastants on the physiology of the biological rhythm maintaining hormone melatonin.


Assuntos
Melanóforos/metabolismo , Neurotransmissores/metabolismo , Piperazinas/metabolismo , Piperazinas/farmacologia , Receptor MT1 de Melatonina/metabolismo , Receptor MT2 de Melatonina/metabolismo , Animais , Carpas , Caseínas/química , Caseínas/metabolismo , Tamanho Celular/efeitos dos fármacos , Denervação , Indóis/metabolismo , Indóis/farmacologia , Melanóforos/citologia , Piperazinas/síntese química , Prazosina/farmacologia , Receptor MT1 de Melatonina/antagonistas & inibidores , Receptor MT2 de Melatonina/antagonistas & inibidores , Receptores Adrenérgicos/efeitos dos fármacos , Receptores Adrenérgicos/metabolismo , Triptaminas/metabolismo , Triptaminas/farmacologia , Ioimbina/farmacologia
7.
Bone Joint J ; 102-B(7_Supple_B): 90-98, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32600193

RESUMO

AIMS: The primary aim of this paper was to outline the processes involved in building the Partners Arthroplasty Registry (PAR), established in April 2016 to capture baseline and outcome data for patients undergoing arthroplasty in a regional healthcare system. A secondary aim was to determine the quality of PAR's data. A tertiary aim was to report preliminary findings from the registry and contributions to quality improvement initiatives and research up to March 2019. METHODS: Structured Query Language was used to obtain data relating to patients who underwent total hip or knee arthroplasty (THA and TKA) from the hospital network's electronic medical record (EMR) system to be included in the PAR. Data were stored in a secure database and visualized in dashboards. Quality assurance of PAR data was performed by review of the medical records. Capture rate was determined by comparing two months of PAR data with operating room schedules. Linear and binary logistic regression models were constructed to determine if length of stay (LOS), discharge to a care home, and readmission rates improved between 2016 and 2019. RESULTS: The PAR captured 16,163 THAs and TKAs between April 2016 and March 2019, performed in seven hospitals by 110 surgeons. Manual comparison to operating schedules showed a 100% capture rate. Review of the records was performed for 2,603 random operations; 2,298 (88.3%) had complete and accurate data. The PAR provided the data for three abstracts presented at international conferences and has led to preoperative mental health treatment as a quality improvement initiative in the participating institutions. For primary THA and TKA surgeries, the LOS decreased significantly (p < 0.001) and the rate of home discharge increased significantly (p < 0.001) between 2016 and 2019. Readmission rates did not correlated with the date of surgery (p = 0.953). CONCLUSION: The PAR has high rates of coverage (the number of patients treated within the Partners healthcare network) and data completion and can be used for both research purposes and quality improvement. The same method of creating a registry that was used in the PAR can be applied to hospitals using similar EMR systems. Cite this article: Bone Joint J 2020;102-B(7 Supple B):90-98.


Assuntos
Artroplastia de Quadril , Artroplastia do Joelho , Automação , Melhoria de Qualidade , Sistema de Registros , Idoso , Confiabilidade dos Dados , Feminino , Humanos , Tempo de Internação/estatística & dados numéricos , Masculino , Sistemas Multi-Institucionais , Alta do Paciente , Readmissão do Paciente/estatística & dados numéricos , Reoperação/estatística & dados numéricos , Estados Unidos
8.
PLoS One ; 13(4): e0196061, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29702675

RESUMO

Global Mobility Networks(GLOMONETs) in wireless communication permits the global roaming services that enable a user to leverage the mobile services in any foreign country. Technological growth in wireless communication is also accompanied by new security threats and challenges. A threat-proof authentication protocol in wireless communication may overcome the security flaws by allowing only legitimate users to access a particular service. Recently, Lee et al. found Mun et al. scheme vulnerable to different attacks and proposed an advanced secure scheme to overcome the security flaws. However, this article points out that Lee et al. scheme lacks user anonymity, inefficient user authentication, vulnerable to replay and DoS attacks and Lack of local password verification. Furthermore, this article presents a more robust anonymous authentication scheme to handle the threats and challenges found in Lee et al.'s protocol. The proposed protocol is formally verified with an automated tool(ProVerif). The proposed protocol has superior efficiency in comparison to the existing protocols.


Assuntos
Segurança Computacional , Privacidade , Tecnologia sem Fio , Algoritmos , Sistemas de Informação
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