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1.
BMC Geriatr ; 24(1): 558, 2024 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-38918715

RESUMO

BACKGROUND: Quantifying the informal caregiver burden is important for understanding the risk factors associated with caregiver overload and for evaluating the effectiveness of services provided in Long-term Care (LTC). OBJECTIVE: This study aimed to develop and validate a Caregiver Strain Index (CSI)-based score for quantifying the informal caregiver burden, while the original dataset did not fully cover evaluation items commonly included in international assessments. Subsequently, we utilized the CSI-based score to pinpoint key caregiver burden risk factors, examine the initial timing of LTC services adoption, and assess the impact of LTC services on reducing caregiver burden. METHODS: The study analyzed over 28,000 LTC cases in Southern Taiwan from August 2019 to December 2022. Through multiple regression analysis, we identified significant risk factors associated with caregiver burden and examined changes in this burden after utilizing various services. Survival analysis was employed to explore the relationship between adopting the first LTC services and varying levels of caregiver burden. RESULTS: We identified 126 significant risk factors for caregiver burden. The most critical factors included caregiving for other disabled family members or children under the age of three (ß = 0.74, p < 0.001), the employment status of the caregiver (ß = 0.30-0.53, p < 0.001), the frailty of the care recipient (ß = 0.28-0.31, p < 0.001), and the behavioral symptoms of dementia in care recipients (ß = 0.28-2.60, p < 0.05). Generally, caregivers facing higher burdens sought LTC services earlier, and providing home care services alleviated the caregiver's burden. CONCLUSION: This comprehensive study suggests policy refinements to recognize high-risk caregivers better early and provide timely support to improve the overall well-being of both informal caregivers and care recipients.


Assuntos
Sobrecarga do Cuidador , Cuidadores , Assistência de Longa Duração , Humanos , Taiwan/epidemiologia , Masculino , Feminino , Sobrecarga do Cuidador/psicologia , Idoso , Cuidadores/psicologia , Assistência de Longa Duração/métodos , Pessoa de Meia-Idade , Fatores de Risco , Idoso de 80 Anos ou mais , Estresse Psicológico/psicologia , Estresse Psicológico/epidemiologia , Adulto
2.
Cancers (Basel) ; 15(18)2023 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-37760567

RESUMO

BACKGROUND: Long-term care (LTC) service demands among cancer patients are significantly understudied, leading to gaps in healthcare resource allocation and policymaking. OBJECTIVE: This study aimed to predict LTC service demands for cancer patients and identify the crucial factors. METHODS: 3333 cases of cancers were included. We further developed two specialized prediction models: a Unified Prediction Model (UPM) and a Category-Specific Prediction Model (CSPM). The UPM offered generalized forecasts by treating all services as identical, while the CSPM built individual predictive models for each specific service type. Sensitivity analysis was also conducted to find optimal usage cutoff points for determining the usage and non-usage cases. RESULTS: Service usage differences in lung, liver, brain, and pancreatic cancers were significant. For the UPM, the top 20 performance model cutoff points were adopted, such as through Logistic Regression (LR), Quadratic Discriminant Analysis (QDA), and XGBoost (XGB), achieving an AUROC range of 0.707 to 0.728. The CSPM demonstrated performance with an AUROC ranging from 0.777 to 0.837 for the top five most frequently used services. The most critical predictive factors were the types of cancer, patients' age and female caregivers, and specific health needs. CONCLUSION: The results of our study provide valuable information for healthcare decisions, resource allocation optimization, and personalized long-term care usage for cancer patients.

4.
Sci Rep ; 12(1): 9668, 2022 06 11.
Artigo em Inglês | MEDLINE | ID: mdl-35690597

RESUMO

Microscopy by Achromatic X-rays With Emission of Laminar Light (MAXWELL) is a new X-ray/visible technique with attractive characteristics including isotropic resolution in all directions, large-volume imaging and high throughput. An ultrathin, laminar X-ray beam produced by a Wolter type I mirror irradiates the sample stimulating the emission of visible light by scintillating nanoparticles, captured by an optical system. Three-dimensional (3D) images are obtained by scanning the specimen with respect to the laminar beam. We implemented and tested the technique with a high-brightness undulator at SPring-8, demonstrating its validity for a variety of specimens. This work was performed under the Synchrotrons for Neuroscience-an Asia-Pacific Strategic Enterprise (SYNAPSE) collaboration.


Assuntos
Microscopia , Síncrotrons , Imageamento Tridimensional , Luz , Microscopia/métodos , Tomografia Computadorizada por Raios X/métodos , Raios X
5.
Zhongguo Gu Shang ; 35(1): 80-4, 2022 Jan 25.
Artigo em Chinês | MEDLINE | ID: mdl-35130605

RESUMO

OBJECTIVE: To explore the clinical application of lockedge suspension combined with three steel wires vertical fixation in comminuted fracture of inferior pole of patella. METHODS: From August 2016 to May 2019, 23 patients with comminuted fracture of the lower pole of the patella, including 14 males and 9 females, were treated with lockedge suspension combined with three steel wires vertical fixation. The age ranged from 34 to 68 (55.0±1.2) years. One year after operation, the pain and function were evaluated by pain visual analogue scale(VAS) and knee flexion and extension range of motion, and the clinical efficacy was evaluated by Lysholm knee score standard. RESULTS: All 23 patients were followed up for 12 to 14, with a mean of(13.0±0.5) months. One patient had skin irritation by the tail of the steel wire, and the rest had no postoperative complications such as incision infection, internal fixation loosening and fracture displacement. The fractures of 23 patients were healed, and the healing time was 10 to 14 weeks with a mean of(12.0±1.1) weeks. The VAS score decreased from 7.96±0.93 before operation to 0.83±0.65 one year after operation. The range of knee flexion and extension activities increased from(20.30±8.69) ° before operation to 1 year after operation(127.39±6.55) °. Lysholm knee score increased from 18.48±4.00 before operation to 96.09±4.91 one year after operation(P<0.05). CONCLUSION: The treatment of comminuted fracture of the lower pole of patella by lockedge suspension combined with three steel wires vertical fixation has reliable fixation and high fracture healing rate. It can meet the requirements of rapid rehabilitation and functional exercise, and the early clinical effect is satisfactory.


Assuntos
Fraturas Ósseas , Fraturas Cominutivas , Adulto , Idoso , Fios Ortopédicos , Feminino , Fixação Interna de Fraturas , Fraturas Ósseas/cirurgia , Fraturas Cominutivas/cirurgia , Humanos , Masculino , Pessoa de Meia-Idade , Patela/cirurgia , Aço , Resultado do Tratamento
6.
Chemosphere ; 294: 133743, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35093424

RESUMO

In Fenton or Fenton-like processes, the key step is to catalyze H2O2 and produce highly reactive OH radicals. More efforts are then focus on designing efficient heterogeneous Fenton catalysts by activating H2O2 to generate OH at the highest possible steady state concentration. In this study, using the antibiotic ofloxacin as target organic pollutant, we firstly demonstrate a point of view for improving OH utilization efficiency by regulating surface chemical reactions to minimizing its migration distance to the target pollutant. C doped g-C3N4 incorporated CuFeO2 (CCN/CuFeO2) exhibited almost ten times higher ofloxacin degradation rate constant than our previously reported CuFeO2 {012} catalyst (0.1634 vs 0.0179 min-1). Since similar amount of OH was generated, the different inhibition effect of tert-butyl alcohol and nitrobenzene on the ofloxacin degradation confirmed that the much-enhanced ofloxacin degradation was attributed to the surface Fenton reaction process. According to XPS and EXAFS characterization, the C-O-Cu bond between g-C3N4 and CuFeO2 established a closed-circuit surface Fenton reaction mechanism. H2O2 was adsorbed and decomposed into OH/O2- over ≡Cu + site in CuFeO2. The successful construction of CCN/CuFeO2 creates a negative surface potential and benefits the enrichment of target antibiotics from water, which greatly reduces the migration distance of OH/O2•- to adjacent pollutant and then increases the OH/O2- utilization efficiency by avoiding the unwanted quenching. Hence, CCN/CuFeO2 possesses superior Fenton catalytic activity and long-term stability.


Assuntos
Peróxido de Hidrogênio , Nanocompostos , Antibacterianos , Catálise , Ofloxacino
7.
Zhongguo Gu Shang ; 34(9): 851-5, 2021 Sep 25.
Artigo em Chinês | MEDLINE | ID: mdl-34569211

RESUMO

OBJECTIVE: To explore clinical effect of arthroscopic meniscus tear strapping suture by rotator cuff suture threader. METHODS: Forty patients with meniscus tear injury admitted from July 2015 to May 2019, including 27 males and 13 females, aged from 20 to 55 years old with an average of (36.0±1.4) years old. Menisci laceration was sutured with rotator cuff suture thread under arthroscopy. Postoperative complication was observed, Lysholm knee joint score before and after operation at 12 months were used to evaluate clinical effects, visual analogue scale (VAS) and range of knee flexion and extension were applied to evaluate recovery of pain and function. RESULTS: All patients were followed up from 12 to 15 months with an average of (12.6±0.7) months.No complication such as joint effusion, suture failure occurred. Two patients occurred mild pain after activity without clinical physical abnormality, and 1 patient manifested moderate pain with joint space tenderness, the other rest without abnormal. Lysholm knee joint score was increased from (49.55±1.21) preoperatively to (98.95±0.42) at 12 months after operation, VAS score decreased from (5.18±0.78)preoperatively to (1.03±0.77) at 12 months after operation, and range of knee joint flexion and extension activity increased from (50.63±9.20)°preoperatively to (130.38±4.99)°after operation, and there were statistical differences in Lysholm knee joint score, VAS and range of knee joint flexion and extension activity (P< 0.05). CONCLUSION: Arthroscopic strapping suture by rotator cuff suture threading device applies to most meniscus injuries, including medial meniscus posterior horn tears, lateral meniscus body tears and lateral meniscus posterior horn tears. This technique meets the need of full-internal meniscus suture without specialmeniscus suture, and has advantages of convenient operation, less complications and good postoperative function.


Assuntos
Lesões do Manguito Rotador , Lesões do Menisco Tibial , Adulto , Artroscopia , Feminino , Humanos , Masculino , Meniscos Tibiais/cirurgia , Pessoa de Meia-Idade , Manguito Rotador , Lesões do Manguito Rotador/cirurgia , Técnicas de Sutura , Suturas/efeitos adversos , Lesões do Menisco Tibial/cirurgia , Resultado do Tratamento , Adulto Jovem
8.
Nanoscale ; 12(30): 16262-16269, 2020 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-32716460

RESUMO

A novel insertable and pseudocapacitive Li+ ion material for highly ordered layered montmorillonite/carbon is explored in the present study. The commercially available protonated montmorillonite and 3,3'-diaminobenzidine act as starting materials to synthesize the layered material via hydrothermal intercalation, oxidative polymerization and carbonization. This method of preparing montmorillonite/carbon nanocomposite exhibits several advantages. To be specific, raw materials are low cost and naturally abundant; the montmorillonite can undergo proton exchange easily to form a permutable proton-type material, and the protons in the layered nanocomposite can be directly substituted by the polymerizable molecules (e.g., 3,3'-diaminobenzidine). Accordingly, a sheet-like montmorillonite/carbon layered nanocomposite is achieved with the carbon stacking on the montmorillonite substrate for the intercalation behavior. As revealed from the electrochemical results, montmorillonite/carbon nanocomposite can deliver a high reversible capacity of 1432 mA h g-1 at 50 mA g-1 and superior rate capacity of 920 mA h g-1 at 10 000 mA g-1 for the lithium ion battery. Furthermore, the full cell with LiFePO4 as cathode and montmorillonite/carbon as anode maintains 94% capacity retention over 50 cycles as well as high coulombic efficiency.

9.
Sci Total Environ ; 723: 138144, 2020 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-32224407

RESUMO

An efficient strategy for enhancing iron efficiency in heterogeneous Fenton reaction via the pyrolysis of ferrocene chemically modified sepiolite (Sep) was proposed in this study. Highly dispersed FeC6 on sepiolite (Fe-Dis@Sep) was synthesized as an efficient photo-Fenton catalyst for the visible light degradation of ofloxacin (OFX). It exhibits an excellent Fenton activity and stability towards OFX degradation. The pseudo-first order reaction rate constant of Fe-Dis@Sep was 5.1-fold higher than that of the supported catalyst with aggregated iron oxides prepared by traditional impregnation method (Fe-Agg@Sep). Based on TEM images and density functional theory (DFT) calculation, the enhanced Fenton activity of Fe-Dis@Sep was attributed to the unique incorporation of FeC6 on Sep via Si-O-C-Fe bond which not only favor the high dispersion of FeC6 with an electron deficiency but also promote Fe(III) to Fe(II) cycle via the formation of surface Fe-H2O2 complex. OH and O2- were identified as active species for OFX degradation in Fe-Dis@Sep-H2O2-Vis system. 98.7% of F and 97.0% of N in OFX was converted into F- and NO3- with a TOC removal efficiency of 89.35%. The possible degradation pathway of OFX was also proposed according to HPLC-MS results. Finally, the Fenton reaction mechanism over Fe-Dis@Sep was discussed.


Assuntos
Compostos Férricos , Ofloxacino , Catálise , Elétrons , Peróxido de Hidrogênio , Silicatos de Magnésio , Oxirredução
10.
Chemosphere ; 236: 124367, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31325831

RESUMO

In this study, the highly dispersed ß-FeOOH on palygorskite (H-ß-FeOOH/PAL) was prepared and investigated as Fenton catalyst for H2O2 activation towards metronidazole (MTZ). Based on electron spin resonance and probe techniques, hydroxyl radicles (•OH) as main reactive oxygen species was confirmed, and much more •OH were generated over H-ß-FeOOH/PAL than T-ß-FeOOH/PAL using traditional impregnation method. The enhanced Fe(III) to Fe(II) cycle due to the highly dispersed ß-FeOOH leads to the fast degradation of metronidazole over H-ß-FeOOH/PAL. 92.8% of MTZ degradation efficiency was achieved within 180 min by adding 17 mmol/L H2O2 and 40 mg/L of H-ß-FeOOH/PAL at pH 6.0. The bacterial cytotoxicity during MTZ degradation process also decreased with reaction time and achieved zero at 66 min, indicating MTZ was not only efficiently degraded but also safely transformed. Besides, the possible MTZ degradation pathway was further proposed based on the intermediates identified by HPLC-MS.


Assuntos
Compostos Férricos/química , Peróxido de Hidrogênio/química , Metronidazol/uso terapêutico , Metronidazol/farmacologia
11.
Zhongguo Gu Shang ; 31(9): 790-793, 2018 Sep 25.
Artigo em Chinês | MEDLINE | ID: mdl-30332868

RESUMO

OBJECTIVE: To explore the clinical effect of modified Metaizeau's technique for radial neck fractures of Judet II or IV in children, summarizing the value of clinical application. METHODS: From May 2014 to March 2017, 32 children of Judet III or IV radial neck fractures were treated with percutaneous Kirschner wire poking reduction and closed reduction with elastic intramedullary nailing fixation, including 21 boys and 11 girls, aged from 5.7 to 10.6 years old with a mean of 7.2 years old. The modified An-Morrey functional rating index were used to evaluate elbow range of motion, myodynamia, stability, and pain preoperatively and 1 year postoperatively in all the patients. RESULTS: All patients were available for an average follow-up from 12 to 15 months. No complications such as incision infection, wire or nail tail irritation and avascular necrosis of radial head and epiphyses was occurred. The fracture achieved solid healing at 8 to 10 weeks after operation. The modified An and Morrey functional score improved from 58.69±5.80 before operation to 99.13±1.79 at 1 year after operation, there was obvious difference of scores between preoperative and postoperative at 1 year. CONCLUSIONS: Modified Metaizeau's technique is a reliable and good treatment for Judet III or IV radial neck fractures in children, which has advantages of few complication, minimal invasion, quick fracture union and good recovery of elbow joint.


Assuntos
Pinos Ortopédicos , Fraturas do Rádio , Criança , Pré-Escolar , Cotovelo , Epífises , Feminino , Humanos , Masculino , Amplitude de Movimento Articular , Estudos Retrospectivos , Resultado do Tratamento
12.
Environ Sci Technol ; 52(11): 6518-6525, 2018 06 05.
Artigo em Inglês | MEDLINE | ID: mdl-29727187

RESUMO

The development of efficient heterogeneous Fenton catalysts is mainly by "trial-and-error" concept and the factor determining H2O2 activation remains elusive. In this work, we demonstrate that suitable facet exposure to elongate O-O bond in H2O2 is the key parameter determining the Fenton catalyst's activity. CuFeO2 nanocubes and nanoplates with different surface facets of {110} and {012} are used to compare the effect of exposed facets on Fenton activity. The results indicate that ofloxacin (OFX) degradation rate by CuFeO2 {012} is four times faster than that of CuFeO2 {110} (0.0408 vs 0.0101 min-1). In CuFeO2 {012}-H2O2 system, OFX is completely removed at a pH range 3.2-10.1. The experimental results and theoretical simulations show that •OH is preferentially formed from the reduction of absorbed H2O2 by electron from CuFeO2 {012} due to suitable elongation of O-O (1.472 Å) bond length in H2O2. By contrast, the O-O bond length is elongated from 1.468 to 3.290 Å by CuFeO2 {110} facet, H2O2 tends to be dissociated into -OH group and passivates {110} facet. Besides, the new formed ≡Fe2+* on CuFeO2 {012} facet can accelerate the redox cycle of Cu and Fe species, leading to excellent long-term stability of CuFeO2 nanoplates.


Assuntos
Poluentes Ambientais , Peróxido de Hidrogênio , Catálise , Ofloxacino , Oxirredução
13.
Sci Rep ; 7: 40185, 2017 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-28054644

RESUMO

Although pressure therapy (PT) represents the standard care for prevention and treatment of hypertrophic scar (HS) from burns, its practice is largely based on empirical evidence and its effectiveness remains controversial. To clarify the effect of PT (15-25 mmHg) for HS, we performed the systematic review and meta-analysis. Several electronic databases were screened to identify related randomized controlled trials (RCTs). 12 RCTs involving 710 patients with 761 HS resulting from burn injuries were included. Compared with non/low-PT, cases treated with PT (15-25 mmHg) showed significant differences in Vancouver Scar Scale score (MD = -0.58, 95% CI = -0.78--0.37), thickness (SMD = -0.25, 95% CI = -0.40--0.11), brightness (MD = 2.00, 95% CI = 0.59-3.42), redness (MD = -0.79, 95% CI = -1.52--0.07), pigmentation (MD = -0.16, 95% CI = -0.32--0.00) and hardness (SMD = -0.65, 95% CI = -1.07--0.23). However, there was no difference in vascularity (MD = 0.03, 95% CI = -0.43-0.48). Our analysis indicated that patients with HS who were managed with PT (15-25 mmHg) showed significant improvements. Due to limitations, more large and well-designed studies are needed to confirm our findings and the side-effects of the PT may also need to be evaluated.


Assuntos
Queimaduras/terapia , Cicatriz Hipertrófica/prevenção & controle , Pressão Hidrostática , Cicatriz Hipertrófica/patologia , Humanos , Ensaios Clínicos Controlados Aleatórios como Assunto , Resultado do Tratamento
14.
Beilstein J Nanotechnol ; 6: 1652-60, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26425415

RESUMO

The main goal of this work is to study the structural and magnetic properties of iron nanowires and iron nanoparticles, which have been fabricated in almost the same processes. The only difference in the synthesis is an application of an external magnetic field in order to form the iron nanowires. Both nanomaterials have been examined by means of transmission electron microscopy, energy dispersive X-ray spectrometry, X-ray diffractometry and Mössbauer spectrometry to determine their structures. Structural investigations confirm that obtained iron nanowires as well as nanoparticles reveal core-shell structures and they are composed of crystalline iron cores that are covered by amorphous or highly defected phases of iron and iron oxides. Magnetic properties have been measured using a vibrating sample magnetometer. The obtained values of coercivity, remanent magnetization, saturation magnetization as well as Curie temperature differ for both studied nanostructures. Higher values of magnetizations are observed for iron nanowires. At the same time, coercivity and Curie temperature are higher for iron nanoparticles.

15.
J Nanosci Nanotechnol ; 10(5): 3155-61, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20358913

RESUMO

In the present study, pure TiO2 and hybrid TiO2/CNTs nanomaterials are prepared by sol gel technique. Post heat treatment is performed at 600, 800, and 1000 degrees C, respectively. The structural characterizations are performed by field emission scanning electron microscopy, transmission electron microscopy, X-ray diffraction and synchrotron X-ray absorption spectroscopy techniques. Experimental results show that anatase to rutile transformation can be observed for pure TiO2 nanomaterials after heat treatment at 800 degrees C. The anatase to rutile transformation is inhibited by carbon nanotubes, and therefore only anatase phases for TiO2 nanomaterials can be observed in the hybrid nanomaterials. The 600 degrees C hybrid nanomaterials show a microstructure with CNTs covered by continuous TiO2 films of numerous small nanoparticles. After applying heat treatment on the hybrid nanomaterials at 1000 degrees C, only TiO2 nanoparticles adhere individually to the uncovered CNTs. Though all hybrid nanomaterials exhibit anatase TiO2, synchrotron X-ray absorption spectra investigations reveal that hybrid TiO2/CNTs exhibit different electronic properties as compared to those of pure TiO2 nanomaterials.

16.
Nanotechnology ; 19(39): 395302, 2008 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-21832591

RESUMO

The fabrication of devices to focus hard x-rays is one of the most difficult-and important-challenges in nanotechnology. Here we show that Fresnel zone plates combining 30 nm external zones and a high aspect ratio finally bring hard x-ray microscopy beyond the 30 nm Rayleigh spatial resolution level and measurable spatial frequencies down to 20-23 nm feature size. After presenting the overall nanofabrication process and the characterization test results, we discuss the potential research impact of these resolution levels.

17.
J Nanosci Nanotechnol ; 7(9): 3081-8, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18019132

RESUMO

Several aromatic compounds derived from benzene by its annelation (naphthalene, anthracene, phenanthrene, pyrene) and exocyclic substitution (e.g., nitrobenzene, dinitrobenzenes, trinitrobenzene, chlorobenzene, N,N-dimethylaniline, and others) and endocyclic substitution (pyridine, quinoline, isoquinoline) efficiently sorbed on multi-walled carbon nanotubes (MWCNTs). Equilibrium constants for the sorption process have been determined. Computations of the energy of formation were performed for surface complexes of those arenes on single-walled carbon nanotubes (SWCNTs). Formation energies of those complexes were correlated against the experimental equilibrium constants. The latter were also correlated against calculated LUMO energy of the arenes. Solely, limited tendencies to the linearity could be observed. The analysis of the results of the correlations indicated that the arenes acting as the charge acceptors formed stronger complexes than arenes with a high electron density in the molecular orbital, for instance, N, N-dimethylaniline. The area of the arene--SWCNT contact was very essential for the complexation. The proximity of the HOMO orbital of SWCNT and LUMO of the arene was another essential factor. Bulky substituents in the arene molecules obscured their efficient contact with SWCNT.


Assuntos
Química Orgânica/métodos , Nanotecnologia/métodos , Nanotubos de Carbono/química , Nanotubos/química , Compostos de Anilina/química , Benzeno/química , Cinética , Microscopia Eletrônica de Transmissão , Modelos Químicos , Nanoestruturas/química , Espectrofotometria , Espectrofotometria Ultravioleta/métodos , Propriedades de Superfície , Temperatura , Fatores de Tempo
18.
Anal Bioanal Chem ; 383(3): 532-8, 2005 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16136306

RESUMO

The remarkable enhancement of electron transfer on screen-printed carbon electrodes (SPCEs) with modification by iron nanoparticles (Fe(nano)), coupled with Fe(CN)(6) (4-/3-) redox species, was characterized with an increase of electroactive area (A (ea)) at electrode surface together with a decrease of heterogeneous electron transfer rate constant (k degrees ) in the system. Hence, Fe(nano)-Fe(CN)(6) (3-) SPCEs with deposition of glucose oxidase (GOD) demonstrated a higher sensitivity to various glucose concentrations than Fe(CN)(6) (3-)/GOD-deposited SPCEs. In addition, an inhibited diffusion current from cyclic voltammograms was also observed with an increase in redox concentration and complicated the estimation of A (ea). Further analysis by the electrochemical impedance method, it was shown that this effect might be resulted from the electrode surface blocking by the products of activated complex decomposition.

19.
J Nanosci Nanotechnol ; 5(3): 479-83, 2005 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15913259

RESUMO

Closed-end single-walled carbon nanotubes were wetted in aqueous solutions of monosaccharides, forming weak surface complexes, as proven by the estimation of the content of monosaccharides in complexes isolated from aqueous solutions. The complexation was confirmed by micro-Raman spectroscopy. The Gaussian 03 (Molecular Mechanics UFF method) computations of total energy of the single-walled carbon nanotube-monosaccharides inclusion and surface complexes showed that inclusion complexes should be more stable than corresponding surface complexes. Computed total energies for particular complexes pointed to a lack of preferences for the formation of complexes with either alpha- or beta-tautomers and either pyranoses or furanoses. The forms preferred in the formation of the surface complexes usually differ from these favored in the formation of the inclusion complexes.


Assuntos
Modelos Químicos , Modelos Moleculares , Monossacarídeos/química , Nanotubos de Carbono/química , Nanotubos de Carbono/ultraestrutura , Água/química , Sítios de Ligação , Simulação por Computador , Cristalização/métodos , Substâncias Macromoleculares/análise , Substâncias Macromoleculares/química , Conformação Molecular , Soluções , Propriedades de Superfície
20.
J Plant Physiol ; 162(3): 355-61, 2005 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15832688

RESUMO

An effective procedure for obtaining healthy shoots from nodal segments of Scrophularia yoshimurae is described. Nodal segments cultured on Murashige and Skoog's (MS) basal medium supplemented with 1.0 mg L(-1) benzyladenine (BA) and 0.2 mg L(-1) alpha-naphthaleneacetic acid (NAA) induced multiple shoots in conical flasks that differed in the way they were closed and sealed. Hermitically sealed culture vessels resulted in high hyperhydricity/vitrification. High concentrations of ethylene and CO2 were found to accumulate in these vessels. The hyperhydricity of the shoot cultures could be decreased by progressively ventilating the vessels. Exchange of gases was achieved by removing the Parafilm sealing without affecting sterility. This reduced the hyperhydricity rate and gave a good recovery of vitrified shoots, but resulted in decreased proliferation and a dehydration of proliferating nodal segments and the culture medium. The best number of normal shoots was observed when the parafilm was removed for gaseous exchange after four weeks of culture incubation. The results show that hyperhydricity in shoot cultures of S. yoshimurae could be prevented by sufficient gas exchange during culture.


Assuntos
Brotos de Planta/fisiologia , Scrophularia/fisiologia , Aerobiose , Dióxido de Carbono/análise , Técnicas de Cultura de Células , Meios de Cultura , Flores/fisiologia , Ácidos Naftalenoacéticos/farmacologia , Brotos de Planta/citologia , Scrophularia/citologia
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