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This study analyzed the efficiency impact of a MOSFET output parasitic capacitance (Coss) on a full-bridge LLC DC/DC converter. The core of the converter was the control chip for a half-bridge LLC DC/DC converter, and the output signal of the chip controlled the first-arm power transistors of the primary side of the converter. The coupling transformer reversed the output signal to control the primary side of the second arm of the power transistor. The full-bridge converter comprises a half-bridge control chip that converts the high-voltage DC power supply to a low-voltage DC power supply, which is then synchronously rectified and supplied to the load. The primary side of the power transistor achieves a zero-voltage switching (ZVS) state through the resonance of the LLC converter. This design gives the converter high power density and a simple structure. Furthermore, to determine the appropriate output parasitic capacitance for improving converter efficiency, this study analyzed the effect of the output parasitic capacitance on the switching loss and conduction loss of the power transistor on the basis of the output parasitic capacitance of the primary-side power transistor. A 1200 W converter prototype was fabricated in this study, and when the output was 300 W, efficiency increased from 92.603% to 93.462%, a 0.859% increase. The empirical results verified the feasibility of the proposed theory.
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Tumour hypoxia plays an important role in modulating tumorigenesis, angiogenesis, invasion, immunosuppression, resistance to treatment, and even maintenance of the stemness of cancer stem cells (CSCs). Moreover, the targeting and treatment of hypoxic cancer cells and CSCs to reduce the influence of tumor hypoxia on cancer therapy remains an imperative clinical problem that needs to be addressed. Since cancer cells upregulate the expression of glucose transporter 1 (GLUT1) through the Warburg effect, we considered the possibility of GLUT1-mediated transcytosis in cancer cells and developed a tumor hypoxia-targeting nanomedicine. Our experimental results indicate that glucosamine-labeled liposomal ceramide can be efficiently transported between cancer cells by GLUT1 transporters and substantially accumulated in the hypoxic area in in vitro CSC spheroids and in vivo tumor xenografts. We also verified the effects of exogenous ceramide on tumor hypoxia, including important bioactivities such as upregulation of p53 and retinoblastoma protein (RB), downregulation of hypoxia-inducible factor-1 alpha (HIF-1α) expression, disruption of the OCT4-SOX2 network of stemness, and inhibition of CD47 and PD-L1 expression. To achieve an ideal therapeutic outcome, we combined treatment of glucosamine-labeled liposomal ceramide with paclitaxel and carboplatin, and we found an excellent synergistic effect, with tumor clearance being noted in three-fourths of the mice. Overall, our findings provide a potential therapeutic strategy for the treatment of cancer.
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Hipóxia , Neoplasias , Humanos , Camundongos , Animais , Transportador de Glucose Tipo 1/metabolismo , Hipóxia/metabolismo , Hipóxia Celular , Lipossomos/farmacologia , Células-Tronco Neoplásicas/metabolismo , Células-Tronco Neoplásicas/patologia , Transcitose , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Linhagem Celular Tumoral , Neoplasias/patologiaRESUMO
This study developed and implemented a driving power supply for light-emitting diode (LED) array streetlamps. The power stage was a quasi-resonant (QR)-flyback converter, its input power was the alternating-current power, and the LED array streetlamp was driven by the direct-current output power. The developed QR-flyback converter was operated in discontinuous conduction mode, and the pulse-width modulation (PWM) control chip was used to switch and conduct at the resonant valley of the drain-source voltage on the metal-oxide-semiconductor field-effect transistor (MOSFET) switch to reduce the switching loss. Moreover, the PWM control chip had a disable function, which was connected with a bright and extinguishable control circuit, and the high/low voltage level signal output by the Arduino development board can be used to control the output power of the QR-flyback converter, achieving bright and extinguishable controls for the LED array streetlamp.
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Electricity is a vital resource for various human activities, supporting customers' lifestyles in today's modern technologically driven society. Effective demand-side management (DSM) can alleviate ever-increasing electricity demands that arise from customers in downstream sectors of a smart grid. Compared with the traditional means of energy management systems, non-intrusive appliance load monitoring (NIALM) monitors relevant electrical appliances in a non-intrusive manner. Fog (edge) computing addresses the need to capture, process and analyze data generated and gathered by Internet of Things (IoT) end devices, and is an advanced IoT paradigm for applications in which resources, such as computing capability, of a central data center acted as cloud computing are placed at the edge of the network. The literature leaves NIALM developed over fog-cloud computing and conducted as part of a home energy management system (HEMS). In this study, a Smart HEMS prototype based on Tridium's Niagara Framework® has been established over fog (edge)-cloud computing, where NIALM as an IoT application in energy management has also been investigated in the framework. The SHEMS prototype established over fog-cloud computing in this study utilizes an artificial neural network-based NIALM approach to non-intrusively monitor relevant electrical appliances without an intrusive deployment of plug-load power meters (smart plugs), where a two-stage NIALM approach is completed. The core entity of the SHEMS prototype is based on a compact, cognitive, embedded IoT controller that connects IoT end devices, such as sensors and meters, and serves as a gateway in a smart house/smart building for residential DSM. As demonstrated and reported in this study, the established SHEMS prototype using the investigated two-stage NIALM approach is feasible and usable.
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BACKGROUND AND OBJECTIVES: Kidd blood group system consists of two major antigens: Jka and Jkb . Both the antigens are absent in individuals typed as Jknull and may develop clinically significant anti-Jk3 antibody. Screening donors for provision of Jknull blood is an ongoing task for blood centres with Jknull blood units kept frozen for specific requirements. In 2016, we discovered a previously typed Jknull donor to be Jka weak positive. Therefore, a study was conducted for our donors to verify Jknull status and to reinforce our typing protocol. MATERIALS AND METHODS: In this experiment, donors previously typed and screened as Jknull were tested with four antisera of Jka and Jkb , and each with gel card for serology testing. Sequence analysis was performed for SLC14A1 gene for the detection of JKnull and weak alleles for genetic testing. RESULTS: Among the 30 samples, four were serologically identified as Jk(a+w ) and genotypically identified as heterozygous for the JK*01W.01 allele. The other 26 were confirmed to be Jknull with JK*02N.01 as the most frequent allele. None of JK*B weak alleles were detected, but three were identified as false positives in the tube method. Gel card gave great accuracy for Jkb detection, but failed to give consistent results for weak Jka . CONCLUSION: By combining the tube method and gel card method in serology, along with complementary genetic testing, the possibility of misinterpreting weak Jka expression was eliminated, and we were able to provide Jknull blood for safe clinical transfusion.
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Genótipo , Sistema do Grupo Sanguíneo Kidd/genética , Sorogrupo , Alelos , Heterozigoto , Humanos , MasculinoRESUMO
We report a new efficient exciplex-forming system consisting of a biscarbazole donor and a triazine-based acceptor. The new exciplex was characterized with a high photoluminescence quantum yield up to 68% and effective thermally activated delayed fluorescence behavior. The BCzPh:3P-T2T (2:1, 30 nm) blend was examined not only as an emitting layer (device D1) but also a reliable co-host of fluorescent and phosphorescent emitters for giving highly efficient exciplex-based organic light-emitting diodes (OLEDs) with a high maximum external quantum efficiency of 15.5 and 29.7% for devices doped with 1 wt % C545T (device D2) and 8 wt % Ir(ppy)2(acac) (device D4), respectively. More strikingly, a strongly enhanced lifetime ( T75 = 16 927 min.) of the C545T-doped device was obtained. The transient electroluminescence measurement as well as capacitance-voltage and impedance-voltage correlations were utilized to explore the factors governing the high efficiency and stability. The obtained results clearly show that the energy transfer and charge transport is highly efficient; they also show the photoelectric semiconducting characteristics of exciplex-based OLEDs, which are significantly different from those of unipolar host-based reference devices D3 (Alq3: 1 wt % C545T) and D5 (CBP: 8 wt % Ir(ppy)2(acac)). Our works have established a systematic protocol to shed light on the mechanisms behind exciplex-based devices. The combined results also confirm the bright prospect of the exciplex-forming system as the co-host for highly efficient and stable OLEDs.
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BACKGROUND: ABO subtypes are characterized by the alteration of antigens present and their expression levels on red blood cells and many are linked to genetic changes in the ABO gene. Weakened expression of antigens should be identified to prevent transfusion reactions or ABO-incompatible transplantations. Genotyping can be applied to identify subtypes to complement serologic testing. Next-generation sequencing (NGS) has shown to provide sensitive and accurate genotyping results as well as valuable cis/trans information. Here we took advantage of NGS and applied it to resolve serology discrepancies in ABO typing. STUDY DESIGN AND METHODS: In this study, we customized capture probes targeting the entire ABO gene and sequenced on MiSeq Illumina. The subtype-causing variants were identified, and cis/trans association to ABO alleles was determined. The results from NGS, serology, and Sanger sequencing were compared. RESULTS: Four control samples typed A, B, O, and AB were correctly genotyped. Of 24 serologically discrepant samples, subtype-causing variations were found in 20 cases, with two unresolved and two identified as weakening of ABO antibody in reverse. The types of variations include 17 known subtype alleles, one novel variant, one novel large deletion, and one microchimerism. Haplotypes encompassing Exons 6 and 7 of ABO were reconstructed in 17 of the 20 samples. CONCLUSION: This study demonstrated a full coverage of ABO by capture-based panel, phasing analysis with NGS in ABO genotyping resolved heterogeneity with novel allele and microchimerism findings. This approach provided a more precise method for subtyping and thereby leading to safer transfusion.
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Sistema ABO de Grupos Sanguíneos/análise , Doadores de Sangue , Tipagem e Reações Cruzadas Sanguíneas/métodos , Técnicas de Genotipagem/métodos , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Análise de Sequência de DNA/métodos , Sistema ABO de Grupos Sanguíneos/genética , Incompatibilidade de Grupos Sanguíneos/diagnóstico , Separação Celular , Quimerismo , DNA/genética , Citometria de Fluxo , Genótipo , Humanos , Íntrons/genética , Polimorfismo de Nucleotídeo Único , Reprodutibilidade dos Testes , Deleção de Sequência , Testes Sorológicos , Reação Transfusional/prevenção & controleRESUMO
BACKGROUND: Healthcare providers have many health-related risk factors that might contribute to urolithiasis: a heavy workload, a stressful workplace, and an unhealthy quality of life. However, the urolithiasis risk in healthcare providers is not clear. METHODS: Using Taiwan's National Health Insurance Research Database, we identified 50,226 physicians, 20,677 pharmacists, 122,357 nurses, and 25,059 other healthcare providers as the study cohort and then randomly selected an identical number of patients who are not healthcare providers (general population) as the comparison cohort for this study. Conditional logistical regression analysis was used to compare the urolithiasis risk between healthcare providers and comparisons. Physician specialty subgroups were also analyzed. RESULTS: Physicians had a lower urolithiasis risk than did the general population (adjusted odds ratio [AOR]: 0.682; 95 % confidence interval [CI]: 0.634-0.732) and other healthcare providers (AOR: 0.661; 95 % CI 0.588-0.742) after adjusting for hypertension, diabetes, hyperlipidemia, coronary artery disease, and residence location. For pharmacists, nurses, and other healthcare providers, the urolithiasis risk was not significantly different than that for general population. Subgroup analysis showed that surgeons and family medicine physicians had a lower urolithiasis risk than did physician comparisons (AOR: 0.778; 95 % CI: 0.630-0.962 and AOR: 0.737; 95 % CI: 0.564-0.962, respectively). CONCLUSIONS: Although job stress and heavy workloads affect physicians' health, physicians had a lower urolithiasis risk than did the general population and other healthcare providers. This might be attributable to their greater medical knowledge and access to healthcare. Our findings provide useful information for public health policy makers about the disease risks of healthcare providers.
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Médicos , Vigilância da População , Urolitíase/etiologia , Adolescente , Adulto , Criança , Pré-Escolar , Estudos de Coortes , Bases de Dados Factuais , Diabetes Mellitus/epidemiologia , Feminino , Humanos , Hipertensão , Lactente , Masculino , Pessoa de Meia-Idade , Programas Nacionais de Saúde , Razão de Chances , Qualidade de Vida , Fatores de Risco , Taiwan/epidemiologia , Urolitíase/epidemiologia , Adulto JovemRESUMO
This paper proposes a new adaptive filter for wind generators that combines instantaneous reactive power compensation technology and current prediction controller, and therefore this system is characterized by low harmonic distortion, high power factor, and small DC-link voltage variations during load disturbances. The performance of the system was first simulated using MATLAB/Simulink, and the possibility of an adaptive digital low-pass filter eliminating current harmonics was confirmed in steady and transient states. Subsequently, a digital signal processor was used to implement an active power filter. The experimental results indicate, that for the rated operation of 2 kVA, the system has a total harmonic distortion of current less than 5.0% and a power factor of 1.0 on the utility side. Thus, the transient performance of the adaptive filter is superior to the traditional digital low-pass filter and is more economical because of its short computation time compared with other types of adaptive filters.
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This study monitored the carbon dioxide (CO2) concentrations and temperatures of three 43-seat tour buses with high-passenger capacities in a course of a three-day, two-night school excursion. Results showed that both driver zones and passenger zones of the tour buses achieved maximum CO2 concentrations of more than 3000 ppm, and maximum daily average concentrations of 2510.6 and 2646.9 ppm, respectively. The findings confirmed that the CO2 concentrations detected in the tour buses exceeded the indoor air quality standard of Taiwan Environmental Protection Administration (8 hr-CO2: 1000 ppm) and the air quality guideline of Hong Kong Environmental Protection Department (1 hr-CO2: 2500 ppm for Level 1 for buses). Observations also showed that high-capacity tour bus cabins with air conditioning system operating in recirculation mode are severely lacking in air exchange rate, which may negatively impact transportation safety. Moreover, the passenger zones were able to maintain a temperature of between 20 and 25°C during travel, which effectively suppresses the dispersion of volatile organic compounds. Finally, the authors suggest that in the journey, increasing the ventilation frequency of tour bus cabin, which is very beneficial to maintain the travel safety and enhance the quality of travel.
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Poluição do Ar/análise , Automóveis , Dióxido de Carbono/análise , Monitoramento Ambiental/métodos , Emissões de Veículos/análise , Hong Kong , Humanos , TaiwanRESUMO
The coupling of specific antibodies to imaging agents often improves imaging specificity. However, free amine groups designed for the coupling can cause nonspecific binding of the imaging agents. We report here development of a nanocarrier, MnMEIO-silane-NH2-mPEG nanoparticles (NPs), consisting of a manganese-doped iron oxide nanoparticle core (MnMEIO), a copolymer shell of silane and amine-functionalized poly(ethylene glycol) (silane-EA-mPEG). The key feature in MnMEIO-silane-NH2-mPEG is the flexible PEG, which masks the non-conjugated reactive amine groups (-NH2 â -NH3(+)) and reduces nonspecific binding of MnMEIO-silane-NH2-mPEG to cells. The amine groups on MnMEIO-silane-NH2-mPEG were conjugated with the fluorescent dye, Cy777 or antibodies [Erbitux (Erb)] to form a MR-optical imaging contrast agent (MnMEIO-silane-NH2-(Erb)-mPEG) for EGFR-expressing tumors. Confocal microscopic and flow cytometric analyses showed that MnMEIO-silane-NH2-(Erb)-mPEG displayed low nonspecific binding. Moreover, TEM images showed that MnMEIO-silane-NH2-(Erb)-mPEG were endocytosed by EGFR-expressing cells. In line with their EGFR expression levels, A431, PC-3, and Colo-205 tumors treated with MnMEIO-silane-NH2-(Erb)-mPEG NPs showed -97.1%, -49.7%, and -2.8% contrast enhancement, respectively, in in vitro T2-weighted MR imaging. In vivo T2-weighted MR imaging and optical images showed that MnMEIO-silane-NH2-(Erb)-mPEG could specifically and effectively target to EGFR-expressing tumors in nude mice; the relative contrast enhancements were 7.94 (at 2 h) and 7.59 (at 24 h) fold higher in A431 tumors as compared to the EGFR-negative Colo-205 tumors. On the contrary, MnMEIO-silane-NH2-(Erb) NPs showed only 1.44 (at 2 h) and 1.52 (at 24 h) fold higher in EGFR-positive tumors as compared to the EGFR-negative tumors. Finally, antibodies can be readily changed to allow imaging of other tumors bearing different antigens. These data indicate that masking surface charges on contrast agents is a useful strategy to improve imaging efficacy.
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Imageamento por Ressonância Magnética , Imagem Óptica/métodos , Polietilenoglicóis/química , Eletricidade Estática , Animais , Linhagem Celular Tumoral , Receptores ErbB/metabolismo , Compostos Férricos/química , Citometria de Fluxo , Humanos , Camundongos , Camundongos Nus , Microscopia Confocal , Nanopartículas/ultraestrutura , Neoplasias/patologia , Polietilenoglicóis/síntese química , Silanos/química , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
The photocatalytic degradation of terbufos in aqueous suspensions was investigated by using titanium dioxide (TiO(2)) as a photocatalyst. About 99% of terbufos was degraded after UV irradiation for 90 min. Factors such as pH of the system, TiO(2) dosage, and presence of anions were found to influence the degradation rate. Photodegradation of terbufos by TiO(2)/UV exhibited pseudo-first-order reaction kinetics, and a reaction quantum yield of 0.289. The electrical energy consumption per order of magnitude for photocatalytic degradation of terbufos was calculated and showed that a moderated efficiency (E(EO)=71 kWh/(m(3)order)) was obtained in TiO(2)/UV process. To obtain a better understanding of the mechanistic details of this TiO(2)-assisted photodegradation of terbufos with UV irradiation, the intermediates of the processes were separated, identified, and characterized by the solid-phase microextraction (SPME) and gas chromatography/mass spectrometry (GC/MS) technique. The probable photodegradation pathways were proposed and discussed.
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Compostos Organotiofosforados/química , Titânio/química , Catálise , Cromatografia Gasosa-Espectrometria de Massas , Cinética , Fotoquímica , Raios UltravioletaRESUMO
BACKGROUND: Blood donors in Taiwan currently are screened for hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus (HIV) infection by immunoassay. The risk of enzyme immunoassay (EIA)-negative, nucleic acid amplification technology (NAT)-reactive donations is not well understood. This study aimed to screen for such donors in Taiwan by a multiplex test (cobas TaqScreen, Roche) on a commercially available NAT system (cobas s 201 system, Roche). STUDY DESIGN AND METHODS: NAT was performed on donors without prescreening in pools of six and NAT-reactive pools were then resolved to the single donation. Individual-donor NAT-reactive samples were discriminated by a commercially available polymerase chain reaction (PCR)-based diagnostic assay (COBAS AmpliScreen, Roche). Samples with EIA- and NAT-discordant results were investigated with supplemental serologic and confirmatory tests. Each sample taken from follow-up of HBV NAT yield cases was tested for HBV serologic profile, NAT, and viral load. The sensitivity and performance efficacy were also evaluated. RESULTS: The 95 percent limit of detection (LOD) for HBV, HCV, and HIV were 5.09, 11.83, and 62.53 IU per mL, respectively. Among 10,727 seronegative donations, 12 HBV NAT yield cases (0.11%) and 1 HCV NAT yield case (0.01%) were detected. Follow-up results for 1 to 8 months showed that the HCV yield case was a window case and all HBV NAT yield cases were occult carriers. CONCLUSION: The use of NAT detected occult HBV and reduced HCV window period. The yield rate, especially occult HBV, was 10- to 100-fold higher than that in developed, HBV nonendemic countries. Therefore, NAT implementation for routine donor screening in a more cost-effective manner should contribute to safer blood transfusion in Taiwan.
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Doadores de Sangue , Hepacivirus/imunologia , Hepatite B/sangue , Hepatite B/diagnóstico , Hepatite C/sangue , Hepatite C/diagnóstico , Programas de Rastreamento/métodos , Biomarcadores/sangue , DNA Viral/genética , Seguimentos , Hepatite B/transmissão , Hepatite B/virologia , Hepatite C/transmissão , Hepatite C/virologia , Humanos , Técnicas de Amplificação de Ácido Nucleico , Projetos Piloto , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , TaiwanRESUMO
In this paper, a simple, cost effective, and potentially universal method is proposed for the formation of high-aspect-ratio nanopillars on various polymers. Our method involves direct reactive ion etching (RIE) using self-formed nanomasks oriented from a dummy material (cover glass). The mechanism is evaluated using nanopillar characterization and surface analysis results from x-ray photoelectron microscopy (XPS) and Auger electron microscopy (AES). By varying the dummy material configuration and modifying the RIE etching time, the distribution and dimensions of the nanopillars can be manipulated to meet a range of requirements. The maximum structural aspect ratio of 60 (6.7 microm high and 112 nm thick nanopillars) can be easily prepared using a 60 min self-masked high-aspect-ratio polymer nanopillars fabrication (SMHAR) process on poly(monochloro-p-xylylene) (Parylene C). Furthermore, nanopillars can also be generated using the same SMHAR process on poly(dimethylsiloxane) (PDMS) and SU-8 photoresist, creating nanostructured PDMS or SU-8 materials in lab-on-a-chip (LOC) or nano/micro-electromechanical systems (N/MEMS).
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This article represents a response to an editorial piece written in Pediatric Exercise Science over 10 years ago by Thomas Rowland in which he debated fitness testing and asked whether the "horse" of fitness testing in schools was dead. Here, the authors revisit the debate and consider the progress that has been made with regard to fitness testing in schools in recent years. On the basis of findings from the literature and some of their research, the authors suggest that accepting the fact that the horse is dead would not be a bad thing. Their advice is certainly to pull tightly on the reigns, slow the horse down, and not allow fitness testing to dominate schools' efforts to promote physical activity.
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Promoção da Saúde/métodos , Educação Física e Treinamento/métodos , Resistência Física , Aptidão Física , Criança , Nível de Saúde , Humanos , Esforço Físico/fisiologia , Instituições Acadêmicas , Esportes/fisiologiaRESUMO
Reactions of Fe(CN)(5)L(3-) (L = 4-aminopyridine (4-ampy), pyridine (py), 4,4'-bipyridine (4,4'-bpy), and pyrazine (pz)) with peroxydisulfate, Fe(CN)(5)L(3-) + S(2)O(8)(2-) right harpoon over left harpoon Fe(CN)(5)L(2-) + SO(4)(-) + SO(4)(2-), have been found to follow an outer-sphere electron transfer mechanism. The specific rate constants of oxidation are 1.45 +/- 0.01, (9.00 +/- 0.02) x 10(-2), (5.60 +/- 0.01) x 10(-2), and (2.89 +/- 0.01) x 10(-2) M(-1) s(-1), for L = 4-ampy, py, 4,4'-bpy, and pz, respectively, at &mgr; = 0.50 M LiClO(4), T = 25 degrees C, pH = 4.4-8.8. The rate constants of oxidation for the corresponding Ru(NH(3))(5)L(2+) complexes were also measured and were found to be faster than those of Fe(CN)(5)L(3-) complexes by a factor of approximately 10(2) even after the corrections for the differences in reduction potentials and in the charges of the complexes. The difference in reactivity may arise from the hydrogen bonding between peroxydisulfate and the ammonia ligands of Ru(NH(3))(5)L(2+) and nonadiabaticity observed in the Fe(CN)(5)L(3-) complexes.