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1.
Anal Chem ; 94(30): 10730-10736, 2022 08 02.
Artigo em Inglês | MEDLINE | ID: mdl-35853147

RESUMO

This study developed a novel luminescent assay for kinase activity using metal-organic coordination polymer nanoparticles (Tb/ATP-Zn) as the probe. Tb/ATP-Zn, self-assembled by adenosine triphosphate (ATP), Zn2+, and Tb3+, is non-luminescent. Protein kinase A (PKA) can catalyze the transformation of ATP within Tb/ATP-Zn nanoparticles to adenosine diphosphate (ADP), which in turn effectively sensitizes the luminescence of Tb3+. Based on this mechanism, Tb/ATP-Zn can realize the facile luminescent "turn-on" sensing of protein kinase activity without the use of external ATP and substrate peptide. Under optimized conditions, the fluorescence intensities of Tb/ATP-Zn at 550 nm are linear with the PKA activity within a range of 0.3-1.5 U·µL-1. The LOD (S/N = 3) of this method is down to 0.001 U·µL-1. The presented assay also features high selectivity, long-term stability, fast response, and convenient operation. Furthermore, Tb/ATP-Zn was successfully employed for monitoring PKA activity in cell lysis solutions. Probe Tb/ATP-Zn is thus expectable to be a powerful tool for the practical study of PKA in relevant biological events.


Assuntos
Elementos da Série dos Lantanídeos , Nanopartículas Metálicas , Trifosfato de Adenosina , Luminescência , Medições Luminescentes/métodos , Polímeros , Proteínas Quinases
2.
Anal Chem ; 92(10): 7240-7248, 2020 05 19.
Artigo em Inglês | MEDLINE | ID: mdl-32323972

RESUMO

The "sample-to-answer" integration and automation of circulating tumor DNA (ctDNA)-based liquid biopsy using digital PCR (dPCR) has been hampered by the complicated operations of liquids with volumes ranging from milliliter samples to nanoliter droplets. On the basis of a "3D extensible" design paradigm proposed previously, an integrated droplet digital PCR (IddPCR) microdevice was successfully developed to automate the entire process of liquid biopsy, from the extraction of ctDNA in 2 mL of plasma using magnetic beads to the generation, amplification, and screening of over 30 000 droplets for detection. A series of reagent mixing structures, including macro-, meso-, and micromixers, was designed to enable efficient reagent handling and mixing at different volume scales. The volume thresholds of the microscale and macroscale in the IddPCR device were calculated to be 40 and 100 µL, respectively, based on the fluid dynamics and sizes of the device structures, so that different mixers can be selected according to the reagent volumes. The DNA extraction efficiency obtained on the device was determined to be ∼60%, and the on-chip ddPCR demonstrated a high correlation with an R2 of 0.9986 between the readouts and the estimations by a Poisson distribution. Finally, the IddPCR microdevice was able to detect rare tumor mutations (T790M) with an occurring frequency as low as ∼1% from 2 mL of human plasma in a "sample-to-answer" manner. This work offers a feasible solution for the automation of liquid biopsy and paves the way for its broad applications in clinics.


Assuntos
DNA Tumoral Circulante/genética , Análise Mutacional de DNA , Reação em Cadeia da Polimerase , DNA Tumoral Circulante/sangue , DNA Tumoral Circulante/isolamento & purificação , Análise Mutacional de DNA/instrumentação , Humanos , Mutação , Reação em Cadeia da Polimerase/instrumentação
3.
Analyst ; 144(16): 4757-4771, 2019 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-31290860

RESUMO

Droplet digital PCR (ddPCR) is a single-molecule amplification technology with broad applications in precision medicine and clinical diagnosis. Dual-fluorescence and four-cluster ddPCR (two/four-ddPCR) assay is an effective way to quantify copy numbers. Currently, two/four-ddPCR data are usually classified with manual thresholds. For clinical applications, automatic and accurate methods are required to avoid subjectivity in diagnosis. Although there are some automatic classification algorithms, their accuracy and robustness still need to be improved to meet the needs of clinical diagnosis. Therefore, a new method is in high demand to automatically classify two/four-ddPCR data in an accurate and robust way. Here, a novel density-watershed algorithm (DWA) method was developed for the accurate, automatic and unsupervised classification of two/four-ddPCR data. First, data gridding was applied to a scatter plot of the fluorescence signal intensity to calculate data densities. Based on the data densities, the watershed algorithm was used to divide the gridded scatter plot into isolated regions automatically. Next, an optimal cluster pattern was determined based on these isolated regions, and excess regions were merged. Finally, the two/four-ddPCR data were classified based on the merged regions, and DNA template copy numbers were calculated accordingly. Using the DWA method for the quantification of both wild types and mutants of epidermal growth factor receptor (EGFR) L858R and T790M, the classification results were highly consistent with expectations, and significantly better than commonly-used automatic algorithms for now. The computed template copy numbers scaled proportionally to the relative concentration of input templates (r2 > 0.998) in four orders of magnitude with a good reproducibility, and achieved a limit of detection over 40 times lower than the commonly-used automatic algorithms. Furthermore, the DWA method was validated on 254 clinical DNA samples derived from frozen tissues, formalin-fixed paraffin-embedded tissues and peripheral blood. In most cases, the DWA method derived accurate and valid classification results. This highly effective DWA method may be widely used for automatically classifying two/four-ddPCR data, and it will greatly promote the application of ddPCR in clinical diagnosis.


Assuntos
Algoritmos , Reação em Cadeia da Polimerase/estatística & dados numéricos , DNA/sangue , Receptores ErbB/genética , Fluorescência , Humanos , Limite de Detecção , Mutação , Distribuição de Poisson , Reprodutibilidade dos Testes
4.
Anal Chem ; 90(21): 12449-12455, 2018 11 06.
Artigo em Inglês | MEDLINE | ID: mdl-30110150

RESUMO

Metal-organic coordination polymers (MOCPs) have been emerging as very attractive nanomaterials due to their tunable nature and diverse applications. Herein, using Tb3+ as the luminescence center, 1,3,5-benzenetricarboxylate (BTC) as building block and Cu2+ as the signal modulator as well as a recognition unit, we propose a novel and effective lanthanide functionalized MOCP (LMOCP) fluorescent sensor (Cu-BTC/Tb) for amyloid ß-peptide (Aß) monomer, a biomarker for Alzheimer disease (AD). Specifically, Cu-BTC/Tb, created by postsynthesis modification strategy under room temperature, is almost nonemissive due to the quenching effect of Cu2+ in the MOCP, exhilaratingly, the presence of Aß1-40 triggered a significant emission enhancement of Cu-BTC/Tb assay due to the high binding affinity of Aß1-40 for Cu2+ and the subsequent suppression of the quenching effect. In the assay, this LMOCP sensor shows high sensitivity with detection limit of 0.3 nM. Due to its capability to eliminate autofluorescence, Cu-BTC/Tb was also applied to the time-gated detection of Aß1-40 in human plasma with promising results. This work presents a novel strategy for the construction of functional luminescent LMOCP for sensitively turn-on fluorescent sensing of Aß1-40. We believe the proposed strategy would inspire the development of various LMOCP-based fluorescent assays or medical imaging platforms for advanced biological implementations.


Assuntos
Peptídeos beta-Amiloides/sangue , Complexos de Coordenação/química , Corantes Fluorescentes/química , Elementos da Série dos Lantanídeos/química , Estruturas Metalorgânicas/química , Polímeros/química , Complexos de Coordenação/síntese química , Fluorescência , Corantes Fluorescentes/síntese química , Voluntários Saudáveis , Humanos , Estruturas Metalorgânicas/síntese química , Estrutura Molecular , Tamanho da Partícula , Polímeros/síntese química , Propriedades de Superfície
5.
Anal Chem ; 90(15): 8919-8926, 2018 08 07.
Artigo em Inglês | MEDLINE | ID: mdl-29987923

RESUMO

Hereditary hearing loss is a common clinical neurosensory disorder in humans and has a high demand for genetic screening. Current screening techniques using peripheral blood or dried blood spots (DBSs) are invasive. Therefore, this study aims to develop a noninvasive and accurate detection method for eight hotspot deafness-associated mutations based on buccal swab and droplet digital PCR (ddPCR). First, this method was evaluated for analytic performance including specificity, detection limit, dynamic range using plasmid DNA. The specificity was 100% and the detection limit was 5 copies. The dynamic range of this ddPCR-based method was from 10 to 105 copies/µL. Next, the method was found to accurately quantify mitochondrial gene heteroplasmy rate as low as 1% for both m.1494C > T and m.1555A > G sites. Then, we demonstrated that buccal swab was a reliable sample. DNA can be extracted and accurately quantified after a buccal swab had been stored for 90 days at either room temperature or -20 °C. Finally, clinical samples (23 DBSs and 42 buccal swabs) were tested to further evaluate the accuracy and clinical applicability of this method. All clinical samples were accurately quantified and genotyped. This noninvasive and accurate method is highly promising as a genetic screening method for deafness-associated mutations due to its high sensitivity and accuracy.


Assuntos
Análise Mutacional de DNA/métodos , Surdez/genética , Adulto , Criança , DNA/genética , Surdez/congênito , Surdez/diagnóstico , Feminino , Testes Genéticos/métodos , Genótipo , Humanos , Recém-Nascido , Masculino , Mutação , Triagem Neonatal/métodos , Reação em Cadeia da Polimerase/métodos , Manejo de Espécimes/métodos , Adulto Jovem
6.
Anal Chem ; 85(22): 11020-5, 2013 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-24191713

RESUMO

Metal organic coordination polymers have received great attention because of their flexible compositions and architecture. Here, we report the design and synthesis of a responsive lanthanide coordination polymer (LCP) for hydrogen sulfide (H2S), utilizing self-assembling of biomolecule nucleotide with luminescent terbium ion (Tb(3+)) and sensitizing silver ion (Ag(+)) in aqueous solution. LCP is highly fluorescent due to the inclusion of Ag(+) ions, which sensitized the fluorescence of Tb(3+) ions. H2S can strongly quench the fluorescence of LCP through its high affinity for Ag(+) ions. Such configurated LCP material from initial building blocks showed high sensitivity and selectivity for H2S and was applied to the determination of H2S in human serum. LCP with Tb(3+) ions also has a long fluorescence lifetime, which allows for time-resolved fluorescence assays, possessing particular advantages to probing H2S in biological systems with autofluorescence.


Assuntos
Sulfeto de Hidrogênio/sangue , Sulfeto de Hidrogênio/química , Elementos da Série dos Lantanídeos/química , Polímeros/síntese química , Fluorescência , Humanos , Elementos da Série dos Lantanídeos/metabolismo , Polímeros/metabolismo , Prata/química , Espectrometria de Fluorescência , Térbio/química
7.
Biosens Bioelectron ; 220: 114890, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36395730

RESUMO

It is of great significance to on-site detection of organophosphate pesticides (OPs) for pollution monitoring and poisoning estimation. Herein, we developed a portable hydrogel test kit for on-site detection of OPs, which is based on the integration of agarose hydrogel with dual-emission coordination polymers (CPs) nanocomposite comprised of Ru(bpy)32+ and zinc (II)-based CPs (ZnCPs) loaded with thioflavin T (ThT). Different from Ru(bpy)32+ with stable fluorescence in acidic environment, ThT@ZnCPs is highly sensitive to H+, which destroys the structure of ZnCPs as a host and quenches ThT@ZnCPs fluorescence. The distinct fluorescence behaviors of Ru(bpy)32+ and ThT@ZnCPs in acidic environment enable the hydrogel test kit to exhibit ratiometric fluorescence responses to acetylcholinesterase (AChE), which hydrolyzes acetylcholine to acetic acid and provides H+. On this basis, combining the inhibition effect of OPs to AChE activity, a ratiometric fluorescence method for OPs detection was established with the hydrogel test kit, and satisfactory results have been achieved in buffered aqueous solutions and apple juice samples. Attractively, by employing smartphone as a signal readout, on-site quantitation of OPs was accomplished with the features of easy to use, portability and low cost, demonstrating a great promising for point-of-care testing in food safety monitoring.


Assuntos
Técnicas Biossensoriais , Inseticidas , Nanocompostos , Hidrogéis , Polímeros , Acetilcolinesterase , Compostos Organofosforados , Organofosfatos
8.
RSC Adv ; 10(43): 25418-25425, 2020 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-35518616

RESUMO

Improving drug utilization of water-based pesticide formulations is facile and feasible to efficiently avoid serious pesticide residues and reduce the resulting environmental pollution. A co-delivery system of two- or multi-pesticides within one formulation could enhance drug efficiency and decrease usage amounts of pesticides due to the synergistic effect of the loaded multiple pesticides. Herein, we reported a porous polylactide (PLA) microcapsule formulation for co-delivery of avermectin (Av) and chlorantraniliprole (CAP). A double emulsion method combined with premix membrane emulsion (PME) was adopted to produce the Av/CAP-loaded porous microcapsules (Av/CAP P-MCs) with prolonged drug release, high loading content and entrapment efficiency, as well as good light and thermal stability. Compared with single Av- or CAP-loaded microcapsule formulations, the Av/CAP P-MCs exhibited higher biotoxicity against Plutella xylostella. These results reveal that the Av/CAP co-delivery system may be a promising candidate to be further explored as a facile, effective and environmentally-friendly pesticide formulation.

9.
Clin Chim Acta ; 510: 88-96, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32645388

RESUMO

BACKGROUND: Droplet digital PCR (ddPCR)-based blood detection of EGFR mutations plays significant roles in the individualized therapy of non-small-cell lung cancer (NSCLC) patients. However, a standard assay that is approved by health authorities is still lacking. Additionally, the proper application of this method in clinical settings also needs further investigation. METHODS: The performance of a newly established ddPCR assay was first evaluated using reference samples and then validated by comparing this method with the amplification refractory mutation system (ARMS) using cell-free DNA (cfDNA) in patients' peripheral blood. Further, the correlation between dynamic quantification of EGFR mutation in the patients and their clinical outcome of tyrosine kinase inhibitors (TKIs) therapy was investigated. RESULTS: A total of 77 patients were included, with 50 in the test group and 27 in the validation group. According to the results of the reference samples and the blood samples in the test group, the cut-off value for patient detection was proposed as mutation rate ≥ 0.1% (total copy number of cfDNA ≥ 1000) or at least one copy of mutation DNA was detected (total copy number of cfDNA < 1000). With this criterion, superior sensitivity of our assay to that of ARMS was observed (P = 0.002 for Ex19Del & L858R and P < 0.001 for T790M). The dynamic quantification of EGFR mutations during TKI therapy indicated that an increase in mutation abundance was correlated with resistance, while a decline was associated with response. Notably, a rebound in mutation abundance during chemotherapy may indicate a desirable chance for TKI re-treatment. CONCLUSION: The novel ddPCR assay showed superior sensitivity in the detection of EGFR mutation in blood. The dynamic quantification of EGFR mutations by this assay would greatly facilitate the administration of TKI therapy, including the monitoring of resistance and response, as well as cohort screening for retreatment.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Carcinoma Pulmonar de Células não Pequenas/diagnóstico , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/genética , Resistencia a Medicamentos Antineoplásicos/genética , Receptores ErbB/genética , Humanos , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Mutação , Reação em Cadeia da Polimerase , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/uso terapêutico
10.
Talanta ; 206: 120200, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31514845

RESUMO

Highly-sensitive and contamination-free droplet digital PCR (ddPCR) is an enabling technology and widely needed for accurate quantification of nucleic acid in clinical applications. In this paper, a novel droplet reader was developed by combining a "quasi" confocal laser-induced fluorescence (LIF) cytometry with a delicate microfluidic chip design. The droplets with a size of 90 µm was illuminated at an out-of-focus position by two aligned laser beams to generate maximum fluorescent signal. Additionally, the lateral offset position of the microfluidic chip should be precisely tuned so that the bandwidth of the FAM and VIC channels were configured at the matching sizes. Then, PMT gain voltages and pneumatic pressures were optimized for better droplet detection efficiencies. An aerosol adsorption experiment was performed to demonstrate that there was no aerosol contamination, and detected copy numbers of both mutants and wild types scaled linearly with the expected input copy numbers (r2>0.998) with a LoB of 0.0 copies and LoD of 3.0 copies. The results demonstrated that this droplet reader with the delicate chip is a convenient, highly-sensitive and contamination-free to detect fluorescence signals inside droplets after ddPCR, which is highly promising for broad applications of ddPCR in clinical diagnosis.


Assuntos
DNA/análise , Dispositivos Lab-On-A-Chip , Técnicas Analíticas Microfluídicas/métodos , Reação em Cadeia da Polimerase/métodos , Desenho de Equipamento , Receptores ErbB/genética , Antígeno HLA-B27/genética , Limite de Detecção , Técnicas Analíticas Microfluídicas/instrumentação , Mutação , Reação em Cadeia da Polimerase/instrumentação
11.
Work ; 63(2): 155-163, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31156197

RESUMO

BACKGROUND: Music and meditation have affirmative effects on the parasympathetic nervous system. OBJECTIVE: To investigate individual preferences for background sounds during meditation, using a series of paired, forced-choice comparisons. METHOD: Interventions included music with a distinct melody (one sample) and without a distinct melody (MWDM) (three samples), nature sounds with embedded alpha brainwave pulses (one sample), alpha brainwave pulses alone (one sample), and silence. Participants rated how much they liked hearing a sample during meditation and whether they felt they could meditate deeply while listening to it. Heart rhythm coherence scores were recorded using HeartMath emWavePro software and hardware. Participants were ranked as novice or adept meditators (NM vs AM) based on coherence scores. Rankings were based on preference selections, rating scales, and coherence scores. RESULTS: Rankings were highest for silence and MWDM. AMs preferred silence, followed by MWDM. NMs preferred listening to MWDM during meditation. DISCUSSION: Those with greater experience preferred meditating in silence. A preference was also seen for a composition style that incorporated altering arrhythmic and rhythmic patterns, and alternating asynchronous and synchronous patterns. CONCLUSION: These results indicate a compelling case for further research investigating meditation, music, and the potential interactive effect of the two on mind, body, and personal performance.


Assuntos
Meditação/métodos , Atenção Plena/métodos , Música/psicologia , Adulto , Idoso , Feminino , Humanos , Masculino , Meditação/psicologia , Pessoa de Meia-Idade , Atenção Plena/normas , Projetos Piloto , Psicometria/instrumentação , Psicometria/métodos , Autorrelato , Inquéritos e Questionários
12.
Mil Med ; 183(suppl_1): 413-420, 2018 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-29635610

RESUMO

Mindfulness meditation training has been shown to reduce stress and improve short-term memory for military personnel. However, no studies have investigated the effects of in-person and virtual world (VW) mindfulness training on Post-Traumatic Stress Disorder (PTSD) or Attention Deficit Hyperactivity Disorder (ADHD) symptoms. In this study, U.S. military active duty service members and veterans were pseudo-randomized into two mindfulness training groups: in-person (IP) and online via a VW, and a wait-list control group. Volunteers answered a demographic questionnaire, and completed the PTSD Checklist-Military Version (PCL-M) and ADHD Current Symptoms Scale before and after training. The results showed practical and clinically relevant reductions in PTSD symptoms, particular for the IP group, but did not show statistical relevance with hypothesis testing. Results also showed post-training reductions in ADHD symptoms for both IP and VW groups, but no change for the control group. To investigate the effects of initial ADHD symptoms, IP and VW groups were combined into a single Mindfulness Training group. Those with high-initial ADHD symptoms attending training showed improvements, but the control group did not. These results expand research on the mindfulness training, and suggest that IP mindfulness training, rather than VW training, may be of greater benefit for those with PTSD symptoms, while either delivery system appears adequate for reducing attentional symptoms.


Assuntos
Transtorno do Deficit de Atenção com Hiperatividade/terapia , Atenção Plena/instrumentação , Psicoterapia/métodos , Transtornos de Estresse Pós-Traumáticos/terapia , Veteranos/psicologia , Adulto , Análise de Variância , Transtorno do Deficit de Atenção com Hiperatividade/psicologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Atenção Plena/métodos , Psicoterapia/instrumentação , Transtornos de Estresse Pós-Traumáticos/psicologia , Inquéritos e Questionários , Estados Unidos , Veteranos/estatística & dados numéricos
13.
J Agric Food Chem ; 66(26): 6561-6568, 2018 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-28489403

RESUMO

Microcapsule formulations have been widely developed and used in agriculture to improve pesticide utilization and reduce environmental pollution. However, commercial formulations of chlorantraniliprole (CAP) are only traditional formulations due to poor solubility of CAP in organic solvents. Here, adopting a solid in oil in water (S/O/W) double-emulsion method combined with premix membrane emulsion, we successfully constructed CAP microcapsule formulations with a high loading content. The microcapsule formulations with good light and thermal stability showed a significantly sustained release for a long period, which could be optimally regulated by tuning the surface porosity and size of the porous microcapsules. Bioassay studies showed that control efficacy of the porous microcapsule formulations against Plutella xylostella was superior to that of the commercial formulation. These results demonstrated that such a porous microcapsule delivery system should have great potential for further exploration as a commercial CAP formulation.


Assuntos
Preparações de Ação Retardada/química , Composição de Medicamentos/métodos , Inseticidas/química , ortoaminobenzoatos/química , Animais , Cápsulas/química , Preparações de Ação Retardada/farmacologia , Emulsões/química , Emulsões/farmacologia , Inseticidas/farmacologia , Mariposas/efeitos dos fármacos , Porosidade , Solubilidade , ortoaminobenzoatos/farmacologia
14.
Talanta ; 164: 427-431, 2017 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-28107952

RESUMO

Lanthanide coordination polymers (LCPs) have emerged as fascinating materials because of their specific structure and properties. In this work, utilizing hydrosoluble biomolecule of guanosine-5'-monophosphate (GMP) as bridging linker, lanthanide terbium ions (Tb3+) as metal nodes, and silver ions (Ag+) as sensitizers, we synthesized a pH responsive luminescent lanthanide CP probe of Tb/GMP/Ag. The probe possesses high luminescence due to the sensitization of Ag+; While in alkaline solutions, Ag+ in Tb/GMP/Ag immediately binds to OH-, forming Ag2O precipitation and resulting in a distinct fluorescence quenching of Tb/GMP/Ag. This probe displays high selectivity for OH- and a broader pH detection range of 7.5-13.0. In addition, based on the high anti-interference ability in serum, we applied Tb/GMP/Ag to measure pH in undiluted human serum samples, yielding satisfactory results.


Assuntos
Substâncias Luminescentes/química , Medições Luminescentes/métodos , Polímeros/química , Soro/química , Térbio/química , Guanosina Monofosfato/química , Humanos , Concentração de Íons de Hidrogênio , Prata/química , Fatores de Tempo , Água/química
15.
Work ; 54(2): 335-50, 2016 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-27259181

RESUMO

BACKGROUND: U.S. military personnel face challenging situations including frequent deployments, family separations, and exposure to war. Identifying coping strategies used by the most resilient service members and veterans could positively influence military resiliency training programs. OBJECTIVE: The purposes of this paper are to investigate the relationship between coping and resilience among U.S. military active service members and veterans, to identify the coping strategies used by those considered most resilient, and to discuss coping and resilience as they relate to the workplace. METHODS: U.S. military active service members and veterans (N = 191) completed a demographic survey and two self-report questionnaires: The 14-Item Resilience Scale [1] and the Brief COPE [2]. RESULTS: Active duty service members had higher resilience scores than veterans (p < 0.05), but both fell into the moderate range. Coping strategies were not significantly different between the two groups (p > 0.05). Active service members' resilience was predicted by their use of positive reframing and less use of self-blame as coping strategies, accounting for 52.3% of the variance (R2 = 0.523, F(2, 60) = 32.92, p = 0.000). Veterans' resilience was predicted by longer time-in-service, greater use of humor, and less use of self-blame as coping strategies, explaining 44.8% of the variance (R2 = 0.448, F(3, 116) = 31.408, p = 0.000). CONCLUSIONS: This research identifies the positive coping strategies, and least-used negative coping strategies, of the U.S. service members and veterans in our study population with higher resilience scores. Incorporating this information into military- or veteran-based resilience training is likely to increase training effectiveness.


Assuntos
Adaptação Psicológica , Emprego , Militares/psicologia , Resiliência Psicológica , Estresse Psicológico/psicologia , Veteranos/psicologia , Local de Trabalho/psicologia , Adulto , Idoso , Feminino , Culpa , Humanos , Masculino , Pessoa de Meia-Idade , Inquéritos e Questionários , Fatores de Tempo , Estados Unidos , Senso de Humor e Humor como Assunto/psicologia , Adulto Jovem
16.
Work ; 54(2): 325-33, 2016 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-27232059

RESUMO

BACKGROUND: Interest in resilience has increased in recent years. The U.S. military focus is on personal health and adaptation following exposure to battle, while the civilian interest centers on adjustments subsequent to disastrous events. Coping skills are also relevant, yet the relationships between coping and resilience are unclear. OBJECTIVE: This brief review examines personal resilience and individual coping strategies, exploring definitions of each, along with their potential relationships to one another. Their potential contributions within a work setting are described. METHODS: A literature review was conducted using search terms of resilience, resiliency, personal resilience, coping and resilient coping. RESULTS: Coping refers to one's using purposeful actions to handle life situations. Coping techniques can be functional or dysfunctional and the situations one copes with may be acute or long term, severe or minor. Resilience refers to positive and functional handling of oneself and ones' life, referring to the ability to recover, recuperate, and regenerate following tragic events. CONCLUSIONS: While coping and resilience are related to one another, they are distinct concepts. Positive coping techniques may contribute to resilience. However, which coping techniques improve resilience, and in what circumstances, are questions for future research.


Assuntos
Adaptação Psicológica , Resiliência Psicológica , Estresse Psicológico/psicologia , Local de Trabalho/psicologia , Humanos , Terminologia como Assunto
17.
Carbohydr Polym ; 136: 341-9, 2016 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-26572364

RESUMO

In recent years, starch microparticles have gained interest in many fields. However, low production, uncontrollable size, and varying size distribution hinder their practical application. Here, we adopt a premix membrane emulsification (PME) method to prepare starch microcapsules at high production rates. The process conditions were optimized to fabricate uniform microcapsules with controllable sizes and narrow size distribution (PDI<0.1). Through encapsulating avermectin (Av), a kind of water-insoluble pesticide, into the shell of the microcapsules in situ during the process, we developed a pesticide delivery system that enabled a controlled and consistent release of Av over a period of 2 weeks. Kinetic analysis indicated that the mechanisms of Av release involved non-Fickian and Case-II transport. The diameters (0.70-4.8 µm) of the microcapsules and Av contents (16-47%) were adjusted to achieve suitable release profiles. The results will lay the foundation for further field experiments.


Assuntos
Cápsulas/síntese química , Inseticidas/química , Ivermectina/análogos & derivados , Amido/química , Cápsulas/química , Emulsões/química , Vidro/química , Ivermectina/química , Membranas Artificiais
18.
Colloids Surf B Biointerfaces ; 144: 38-45, 2016 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-27062215

RESUMO

Conventional pesticides usually need to be used in more than recommended dosages due to their loss and degradation, which results in a large waste of resources and serious environmental pollution. Encapsulation of pesticides in biodegradable carriers is a feasible approach to develop environment-friendly and efficient controlled-release delivery system. In this work, we fabricated three kinds of polylactic acid (PLA) carriers including microspheres, microcapsules, and porous microcapsules for controlled delivery of Lambda-Cyhalothrin (LC) via premix membrane emulsification (PME). The microcapsule delivery system had better water dispersion than the other two systems. Various microcapsules with a high LC contents as much as 40% and tunable sizes from 0.68 to 4.6µm were constructed by manipulating the process parameters. Compared with LC technical and commercial microcapsule formulation, the microcapsule systems showed a significantly sustained release of LC for a longer period. The LC release triggered by LC diffusion and matrix degradation could be optimally regulated by tuning LC contents and particle sizes of the microcapsules. This multi-regulated release capability is of great significance to achieve the precisely controlled release of pesticides. A preliminary bioassay against plutella xylostella revealed that 0.68µm LC-loaded microcapsules with good UV and thermal stability exhibited an activity similar to a commercial microcapsule formulation. These results demonstrated such an aqueous microcapsule delivery system had a great potential to be further explored for developing an effective and environmentally friendly pesticide-release formulation.


Assuntos
Microesferas , Praguicidas/análise , Poliésteres/química , Biodegradação Ambiental , Bioensaio , Cápsulas , Preparações de Ação Retardada , Microscopia Eletrônica de Varredura , Nitrilas/análise , Tamanho da Partícula , Fotólise/efeitos da radiação , Piretrinas/análise , Raios Ultravioleta
19.
Spectrochim Acta A Mol Biomol Spectrosc ; 165: 150-154, 2016 08 05.
Artigo em Inglês | MEDLINE | ID: mdl-27131874

RESUMO

A new ruthenium-based complex 1 [(bis(4,4'-dimethylphosphonic-2,2'-bipyridine) dithiocyanato ruthenium (II))] was developed as a colorimetric probe for the detection of Hg(II) and Cys (Cysteine). The obtained compound 1 can give interconversional color changes upon the alternating addition of Hg(II) and Cys in 100% aqueous solution. The specific coordination between NCS groups with Hg(II) can lead to the formation of 1-Hg(2+) complex, which can induce a remarkable spectral changes of probe 1. Afterwards the formed 1-Hg(2+) complex can act as effective colorimetric sensor for Cys. Owing to the stronger binding affinity of sulfhydryl group to Hg(2+), Cys can extract Hg(2+) from 1-Hg(2+) complex resulting in the release of 1 and the revival of absorption profile of the probe 1. By introducing the hydrophilic phosphonic acid groups, the proposed probe exhibited excellent water solubility. The limits of detection (LODs) of the assay for Hg(2+) and Cys are calculated to be 15nM and 200nM, respectively.

20.
Anal Chim Acta ; 912: 139-45, 2016 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-26920783

RESUMO

Lanthanide coordination polymers (LCPs) have recently emerged as attractive biosensor materials due to their flexible components, high tailorable properties and unique luminescence features. In this work, we designed a smart LCP probe of Tb-CIP/AMP {(CIP, ciprofloxacin) (AMP, adenosine monophosphate)} for Hg(2+) detection by using lanthanide ions as metal nodes, CIP as ligand molecule, and AMP as bridging linker and recognition unit. Tb-CIP/AMP emits strong green luminescence due to the inclusion of AMP, which withdraws the coordinated water molecules and shields Tb(3+) from the quenching effect of O-H vibration in water molecules. The subsequent addition of Hg(2+) into Tb-CIP/AMP can strongly quench the fluorescence because of the specific coordination interaction between AMP and Hg(2+). As a kind of Hg(2+) nanosensor, the probe exhibited excellent selectivity for Hg(2+) and high sensitivity with detection limit of 0.16 nM. In addition, the probe has long fluorescence lifetime up to millisecond and has been applied to detect Hg(2+) in drinking water and human urine samples with satisfactory results. We envision that our strategy, in the future, could be extended to the designation of other LCP-based hypersensitive time-gated luminescence assays in biological media and biomedical imaging.


Assuntos
Corantes Fluorescentes/química , Elementos da Série dos Lantanídeos/química , Mercúrio/análise , Polímeros/química , Humanos , Microscopia Eletrônica de Varredura , Espectrometria de Fluorescência , Abastecimento de Água
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